TrainLine booking issues

It is very unlikely that first class would be full on any given train.
However this is what happens when you purchase train tickets too far in advance.
The same would have happened if you had booked the same trains direct with the relevant train companies, except that you should have had the chance to see that was happening, although it is easy to miss.
Trains are frequently opened for booking before seat reservations are available.
It is not a problem. It should be possible to track direct on the train companies own websites when seat reservations open for the dates of travel, and reserve seats then.
You can book a seat at any staffed station until a few hours before travel, in some cases up to 15 minutes beforehand.
Often that happens because train times are unconfirmed due to potential engineering work.
On many companies seat reservations open 6 to 8 weeks before travel, often less. That is more than ample time.
You will not be "wandering the train looking for a seat".
Caveat Emptor. In the UK always book direct, not with third parties.
By " no seats available" they mean "seats not yet opened for booking" not "seats sold out"

That makes me feel a little better. Thank you. Why didn’t their chat agent explain this to me? Another reason not to use them. I appreciate you taking the time to respond.

Clearly I am not privy to the chat conversation, but I think this was probably just two people misinterpreting each other. Maybe the agent was having a bad day and was a little curter than might have been ideal.
But yes really a lesson to learn from, both for the OP and for anyone else.
Maybe I was a little short earlier as well, and could have explained better and more helpfully that generally when a train company issues advance tickets is usually the clue that seats can now be reserved. There are doubtless exceptions, but it is a really good guide point.

Most people involved in the railway business in Europe are Europeans, and look at train travel the way Europeans do. So they may be unprepared for the expectations non Europeans have. Non Europeans often expect train travel to be like air travel, but at ground level, where Europeans expect train travel to be mass transit. Like taking the subway, but over a longer distance.

Europeans typically do not book train tickets weeks in advance, and often do indeed not bother with getting reservations. Finding a seat for yourself is something we are used to, and usually expect. We also know that tickets are for travel, not for seats. Your ticket is a prove you have paid for transport. So being able to buy a ticket when it is not possible to reserve a seat is entirely expected here. It is probably your ticket is even flexible. So the railway company actually doesn't even know (or care) what train you intend to use it on.

Of course, reservations after purchase are still possible. If you want, just go to a station, and get a reservation for the train you want to take.

there are also train companies here who offer first class but no reservations at all. London Northwestern is one of those.

It is also possible that TrainLine has sold tickets not yet officially released because they know they will be. And there are strikes.

Maybe if you mentioned your dates of travel, or at least approximately, and the routes you are travelling on we could give more precise advice,

Sorry you have been having a tough time...

(oh and welcome to the Forums!!)

Thanks to everyone for their sage advice and counsel.

So I know this might not really help the original poster, but it does bring up an opportunity to point out one of the key tenants of travel.

Book direct. You don’t need a middleman between you and the airline, you in the train company, etc. book direct!

And why didn’t the chat agent tell you what you needed to know, probably because they didn’t have the information. Their goal is to just get you off of the chat so they can go on to somebody else. Good information is not necessarily important to them.😢

Trainline is actually pretty good, and really does an effort at making the ticket buying process a bit less confusing for tourists. They are the best place to buy tickets for Spain, and for International trips in/out of France.

That the agent could not answer "why do you sell tickets when there are no seats available" is most likely because he was surprised buy the question. A European wouldn't ask this question.

The correct answer btw. would have been " because railways are a public service, and thus we must sell tickets".

I would like to thank all repliers for their constructive comments. Perhaps I can close this thread with these final comments. First, I always deal directly with the provider of services for those services with which I am familiar - airlines, car rentals, hotels, etc. Even when traveling in France, I deal with SNCF directly. However, I am not at all familiar with the rail system in the UK. All the relatively small regional railways make it difficult for a foreigner like me to navigate. At a start, I don't even know which companies go where. In fact, in the three return day trips I am taking out of London, it turns out they are on three different railways. One of them I did look at booking directly, and they wanted me to enter my mobile number - and they said it must be 10 digits and begin with "0". My US based mobile number is 10 digits beginning with "1", but they wouldn't accept that and they wouldn't let me book without it. They didn't seem geared towards an overseas purchase. The reason I chose Trainline is that I could book all three trips in one session, that they would deliver the tickets to me directly via email, and that they would help me sort through the various ticket options. All three of those things they did, and they did well. What irked me is that they asked for my seating preference, and told me the exact seats would be on my tickets. Then after I paid, they sent me the tickets (immediately, I might add) and it was not until I looked at them that I found the seat numbers blank. As a naive user of the UK rail system, I found this very misleading. Then when I created a chat session with them, all they told me was that there were no seats available. They didn't explain why. That, I felt, was a poor response. Thanks again for all the expertise the forum users have shared.

For future reference, you should be able to see all the available rail options (except for special tourist trains, I guess), run by all the rail companies on the NationalRail.co.uk website. You don't need to start out knowing who runs trains to your planned destination, which is helpful since you may have options for the departure station as well as for the operating company. After you choose the specific departure you want, the National Rail website will transfer you to the website of the operating company.

I've never had an issue buying that way, but it has been reported here that some are easier to use than others, and that you can buy a ticket on a Company X train on the Company Y website.

look at Trainline for Lucerne to Como, is Trainline legit?

Trainline are legitimate, yes, third party resellers, but legitimate.
For Lucerne to Como there is no obvious reason not to buy your tickets direct from the operators, rather than (any) 3rd party. In this case SBB or Trenitalia. It will save money, but far more importantly, make hand!ing any problems which arise so much easier.