I have a similar view to Badger. My view says that Rick employs and pays staff, and also employs and pays local guides to write his website material.
There simply is no valid reason why I would volunteer on this forum to rewrite it, as opposed to giving personal advice for specific journeys which is what this forum is really about.
I know that RS used to sell BritRail passes (not now), presumably hence why he concentrates on them, which is fine. The Man in Seat 61 has some biases like that, of who pays him commission for referrals. Again, if you know that, there is nothing wrong in it.
I assume it is accurate that many of the regional passes don't offer child and senior concessions. If it is then I would very much suspect that where domestic passes exist for some of the Britrail ones the domestic ones are cheaper than the Britrail ones.
We now have Britrail passes on our domestic ticket machines in the North of England- but with dummy or nil fares assigned, so it is hard to compare definitively.
But even as starter for 10 information, I find the UK rail information to be rather dated. At times on the forum that shows when people ask questions about trains which don't exist in the manner expected.
I also accept that personally, due to what I do in 'real life' I drill down into more detail than a website overview could or should handle, so that also disqualifies me.
One little thing does surprise me- that he implies that you can have a berth in a shared sleeper train cabin for around $75. Shared cabins (2 strangers) came to an end during the pandemic era, and a sleeper cabin on Cal Sleeper is now an awful lot more than $75. The Great Western Night Riviera Sleeper is much better priced, but even there $75 is an optimistic price.
While he may be right I am surprised that a reservation on a South Eastern domestic HS1 train costs $5 with a Britrail pass. I believe that is free now- may have been a charge at one stage for all I know.
There you are, too much detail again.