I mostly agree, but I don't think it has to be an either-or.
See this quite a bit in long-running comics - superman, batman, etc - that go through different waves of good/bad/polarizing/etc. since they've been around for so long.
And sometimes, even the money-driven remakes/reboots in film are good, too.
But sometimes, they are bad.
I would contrast with Star Wars - some of the most interesting pieces in the franchise came from "extended universe" stuff (KOTOR, prequel trilogy, Mandalorian, etc.), but some of the stuff has not been great (don't want to get into details of what I personally dislike for obvious reasons). And it gets even more contentious when "new" stuff overwrites "old" stuff (like with the legends/canon retcon in star wars... though we've also seen this in comics many times as well).
But arguably, the original trilogy itself almost feels like a separate story/universe from everything surrounding it. It's not just a case of consumerist/profit-driven greed, it's an inevitability of having so many different writers work on a franchise (and this is going back to original EU books), even if there is some central direction from one person. Same could even be said for ATLA vs Korra - I didn't dislike Korra, but they are fundamentally different stories, even if they are within the same "universe" and have a lot of the same creators.
Perhaps DC comics being my first "big" fandom has inured me to some of this stuff... not liking a new author or new retcon just means I don't buy the new stuff, it doesn't mean I'm not going to engage with the old stuff any more.
And I can also understand getting frustrated when there's too much "new" stuff in fandom content (whenever I look up Flash fanfiction, I end up excluding everything tagged with CW stuff. And the CW show was well-received, but it wasn't what I saw as Flash).
I don't know when the right time is to "kill" a story/franchise. And that's not even getting into fanfic/fanart/etc. where you are repeatedly beating the "dead horse" of the franchise, albeit for love and not money.
And maybe that's part of it, too - I loved the Mandalorian tv series. And I enjoyed the Mandalorian & Grogu movie - but structurally, the movie was not good. If all of the characters in it were completely brand new (e.g., I didn't already have an emotional connection with the franchise), I probably would not have enjoyed it. There wasn't the same level of detail payed to the emotional/philosophical throughline that I would expect for a good story. Frankly, I struggle to identify what the film's internal conflict actually was.
But it was cool to see a lot of familiar faces. Maybe I'm part of the problem.