10ish day itinerary Amsterdam, Paris, Swiss Alps is this doable or advised?

I would review the posts here on the Forum under the respective countries, as there's a wealth of info already posted. I would recommend a few more days. How many nights on the ground will you actually have? Flying open jaw is probably the best.
Many folks here report the prices of European lodging is increasing, and availability decreasing, due to pent-up post- COVID demand. Probably best to research accommodations asap,
Safe travels!

I just don’t get wanting to visit 3 countries in such a short time. Stay in one of those places. Plenty to see and do.

I would cut out one of those places. For me, I’d cut Amsterdam. Then considering fly into one (say Paris) and out of the other (Zurich). Your itinerary doesn’t take into consideration getting to the city where you’ll fly out of. If your last stop is the Swiss alps (Lauterbrunnen, Wengen or Murren would be my choice), you need to travel to Zurich (or maybe Lucerne if you have an afternoon flight) the day before your departure.

Two days would be very inadequate time for me in all of those places, and your itinerary, as sketched out, has you relocating on 4 of your 10 days, which I would find very hectic. Traveling all the way from Paris to the Alps for just two days at the destination could turn out to be disappointing if you hit bad mountain weather. I've seen it so bad (due to rain and fog) that one could hardly see the views outside the train window.

The train route from Paris to Lauterbrunnen, a popular area of the Bernese Oberland, takes 6 hours or more. A bit of extra time is required to get to the villages higher up in the mountains. Note that those train tickets can be very expensive--I see rates up to and even exceeding €200 one way. If you stayed longer in Switzerland, some form of Swiss rail card might pay off. One option is a half-fare card.

Does your "Day 1 - Travel to Amsterdam" mean
a) the day you depart the States to go to Europe; or
b) the day your flight arrives in Amsterdam ?

Happy anniversary!!

your day 1.

You are somewhere in the US, yes? Is day 1 pack up, go to airport, fly during the day, arrive in Amsterdam? Or is it pack up, go to airport, start flying overnight, arrive the morning of day 2 in Amsterdam?

I ask because the vast number of flights from most parts of the US to Europe are the second option. In which case you will lose more of your first Amsterdam day, in addition to jetlag which you will likely get either way.

How were your London and Italy trips for jetlag? Was one of you worse than the other, or were you both dragging for a couple of days, or no effects on either?

I wonder with 3 fairly remote from each other locations what draws you to those in particular. I get your comments about the cruise.

I wonder that you give the same amount of time to each of your three destinations when they are so different from each other. Have you worked out what you want to see in Amsterdam, Paris and Switzerland, and they just wound up that long?

Be aware of weather in the Alps. Bad weather and you will be wishing you had a few more days there (I tend to go for 5 nights at a time) because the fabulous stuff prefers good weather, preferably nearly cloud free.

I get that you want to see as much as your can, but I'd spend more time in each. It is interesting to see your mathematical progression. First trip two places adjacent. Second trip, 4 places adjacent, third trip 3 places in three countries.

On your travel days do you expect to fly, take the train or drive?

I am not one who thinks you must see everything in a city like Paris, but if I was going to give Paris just a glance, I would be combining it with somewhere in the French countryside a short train ride or drive away, not spending all that time on the train for short visits. And I always give somewhere at least four days. I think you will feel very shortchanged by the time you get to the Alps (and have to turn around and leave). I would think long and hard about whether this much moving is going to pleasant or cost effective. A nice alternative would be to fly to Geneva, experience some of the French region of Switzerland, then the Alps.
Or, just Paris and Amsterdam would be reasonable, with some side trips.

Doable? Yes. Advisable? IMO, no. At listed, you are shortchanging every one of those locations, and I think, in the end, would leave you feeling unsatisfied. I think you should strongly consider eliminating one of your choices. And DO look at buying multicity (open jaw) tickets to avoid having to backtrack for your departure.

I'm on the side of dropping one destination and dividing those days between the other 2. Either Amsterdam and Paris or Paris and Switzerland.

If you did Amsterdam and Paris, I'd do 4 nights in Amsterdam and the rest in Paris.

And yes, I'd do as many days as you can just for the 2 locations. If you can, particularly as we are not sure what you are thinking with arrival Day 1 in Amsterdam - meaning you left on Day 0?

Thank you all so much for your advice! I think I knew it was a stretch to hit all 3 of these locations, but I needed to hear your wisdom. We probably have some of the post-covid travel excitement and want to see it all. We also haven't been on a big vacation since 2015.

I agree that if we want to leave our travels feeling satisfied, we need to drop a location or 2 and spend more time in the locations we select. Now we just need to decide which of these regions we should focus on.

Rethinking things, would any of these plans be advisable:
1. Alps with some northern Italy.
2. Alps with a little France.
3. Just stick to Switzerland.
3. Amsterdam, Paris and French countryside.
4. Just stick to France.

I'd love any advice or opinions!

I'm going to be no help with your new choices OP. They would all work.

Oh, and I wasn't at all accounting for a huge time change in our travels from the US to Europe. I definitely had a day zero that I didn't include. Our 12ish days will need to encompass all travel to and from the US.

If you can only travel in the summer, I would advise Switzerland, because of the European heat. The Swiss cities can get a little warm, but the temps in the Alp very nice.
You really are a little late to be planning a European summer trip, because of the pent-up post- COVID demand. Start researching available lodging asap.
Hope it all works out!

As for you new ideas:

Rethinking things, would any of these plans be advisable:
1. Alps with some northern Italy.
2. Alps with a little France.
3. Just stick to Switzerland.
4. Amsterdam, Paris and French countryside.
5. Just stick to France.

Since your 12 days in includes travel, that give you 10 days on the ground, or 11 nights. You lose a day when traveling there, and your departure day. I still would stick with 2 locations. Your day of travel from one place to the other may be a long day.

Now you just need to decide what you want to see/do. You might consider flying into Zurich and taking the train to Wengen. Stay 5 nights. Then take the train to Colmar. Stay 5 nights. Visit Strasbourg and the beautiful villages near Colmar. You could fly home from Frankfurt (3 hr bus from Strasbourg), or Paris. You probably want to spend the night wherever you fly out of, just in case.