Well....I'm going to be the music critic (someone has to be...) and point out that 'stylistic changes' may save band's careers but it rarely leads to their best music and usually alienates earlier fans.
I have no problem with an artist changing musical priorities. It might be chasing chart success or exploring artistic freedom or something more personal. It's their right and it's my right to buy the record or not buy the record. I think 'best' music is very subjective, who is it 'best' for? I've heard highly personal releases that I think are crap but the artist claims it was therapeutic for them.
I will add that you are spot on when you say earlier fans often want no part of the changes. There are several bands I essentially walked away from because I didn't like what they were putting out. A mutual parting of the ways!
The most popular Asia lp (rating on PA 3.24) was still the first and they never got past 3.34 rating on Prog Rock archives and that was for Arena 1996. The first is the only one I own.
I can understand using Billboard chart and sales success as a reference point for a high level view. I don't understand judging releases based on somebody else's rating system, I prefer the grading system of my own ears! However...nobody has time to listen to everything so I understand if people screen their listening through a rating service.
I've found that RYM is good for information.
https://rateyourmusic.com/artist/asia
Even this site has a ratings and rankings that I ignore but I do like the completeness of the discographies and the posted reviews.
Is there a thread on this site where people list sites for gathering information? I'm always looking to expand.
I actually have a pet peeve that dovetails into this. I see all sorts of revisionist history written with retro reviewing. Sure, it is interesting to read what a 30 year old music journalist says about 50 year old albums but I find more value in reading what Lester Bangs had to say!
I'm a fan of The Moody Blues and have all the early lps up to and including LDV (1981). Their best by far
imho was 'Chidrens Children' in 1969 though some hard core prog fans say 'Days Of Future Passed' was their best and they never bettered it. IMHO they never reached their best work again after Seventh Sojourn.
I agree that there are few similarities between early Moody Blues and the band we heard in the '80's! I can listen to both, they're just different.