Like most of us on this forum, I easily prefer to take the train vs flying so long as I'm not in a big hurry to get there, and even THEN, that's up for debate....
I talk about taking the train enough to friends that a lot of them are actually starting to ask serious questions to me about train travel beyond commuter trains and subways.....I try to tell them a long distance train isn't just a way to get there....It's a way to enjoy the journey...and it beats the snot out of driving.
What do you all say when you're asked about your train adventures?
It all depends

-- on
A) who's asking and what do they need?
B) where are they planning to go (and when)
C) what travel experiences have they had, what modes?
D) what they personally like (or hate) about particular trips
In any case I don't try to sell anybody on Amtrak. No proselytizing. Waste of time. As others have posted.
For example, a co-worker who already knew that Amtrak from MSP to Wolf Point would be way cheaper than flying and way less stressful than driving . And could sleep on the way in coach after a 12 hour shift. I looked up the on-time performance and showed it to him,
Or, the bus driver (Mohammed) who was amazed that there is a train from MSP to Seattle. For him, it all depends on cost, and maybe with free or half-fare dependents, it might work, he's gotta balance the cost of the fare against taking an extra day off work.
Or, my daughter, who took the EB (and the LSL) several times, but now, with serious college and all, needs the cheapest fastest way to visit her friends in Seattle (from MSP)
In general, for the western LD trains, I say
It's a lot slower, the seating is great, the scenery (and the history and natural history is worth a trip sometime), the roomettes are sometimes cheap, depends what you want.
It just all depends on individual needs, wants.
So, if friends or acquaintances ask, I try to grok what they are looking for. If I think they might enjoy a LD train ride,
then maybe we get into the details.
Again YMMV