Whenever people see old systems still in production (say things that are over 30 years old) the assumption is that management refused to fund the replacement. But if you look at replacement projects so many of them are such dismal failures that's management's reluctance to engage in fixing stuff is understandable.
From the outside, decline always looks like a choice, because the exact form the decline takes was chosen. The issue is that all the choices are bad.
None of the things you said are actually true. Only superficially, because you've only seen those mass market crap.
Good movies are still around, and yuo don't even notice the CGI, because they're cleverly done. For crap like the recently released snow white, it's obvious that the CGI is badly done - it doesn't make it an indictment against all movies released of late!
Same with games - just because there's lots of AAA studio flops that look terrible, doesn't mean the medium is all terrible. There's so many good indie games that you can never truly play them all.
But if your exposure to these products are only the mass market crap, then you might certainly feel that way.
Compare 1997 to today.
Major hit after major hit was being released that year, and they were overwhelmingly original and creative. There had been a boom in independent filmmaking and many of the big production houses had started up smaller studios to attract the talent. Unfortunately, Hollywood did what Hollywood does and killed everything that made them good.
Nowadays, we have endless releases of super hero sequels that are, fundamentally, the same movie over and over. We have endless remakes and reboots because nobody wants to take a chance.
Yes, you can find creativity if you look hard enough, but in 1997 it was everywhere, and in your face. You can't pretend that it doesn't matter or that it doesn't mark an enormous shift in culture (business and society).
What's worse is that comedy is a minefield, as somebody somewhere is bound to be offended and launch a cancel campaign. So comedy films, including the once-beloved rom com, just don't get produced anymore like they used to. Any attempts at humor in movies has to be rolled in to something else -- superheroes talking in aggressively annoying Whedonese and the like -- and housewives must content themselves with Hallmark Channel glurge. And what humor is there is cringey as fuck because it's either entirely toothless or it's a "Straight white men, am I right?" type of thing because you are still allowed -- and encouraged -- to mock that group.
I mean, the normally sequel-averse Jim Carrey came back to do three movies about a video game hedgehog because those are the only movies being made in which he gets to flat-out do Jim Carrey stuff.
So there has been something of a renaissance with television, starting around the time of the Sopranos release in 1999 I think, which there was a market for shows which didn't 'reset' somewhat between episodes.
Uh. 1997 had Oz, Buffy the Vampire Slayer, Stargate SG-1, King of the Hill, Just Shoot Me, Ally McBeal, The X-Files, Friends, 3rd Rock from the Sun, and MTV still showed music videos. Cable television hadn't yet been completely overrun with 'reality' television. We joked about The History Channel becoming the WWII channel, but it hadn't yet become the Ancient Aliens, cheap, pseudo-reality parody of itself.
I get your point about serialized stories, but I'd still take the great entertainment of the 90s over today's over-reliance on digital effects and low-quality writing to generate cheap drama. Besides, most shows aren't written with a set arc, they just keep writing more so long as the numbers stay up. So we get a couple of seasons of increasing drama and mystery, then it gets cancelled with no payoff. I'd rather have the amnesia-based reset system than that!