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.
I mean, like, Disney has been getting worse at CGI, but only because then whole company has given up. This is just normal companies shifting around, though.
The problem with CGI today is that it's over-used and mis-applied in areas that still have Uncanny Valley type issues (fight scenes, car chases/crashes, etc).
I think that's the main point, yes. There's a sense before that companies were trying to push the envelope. These days it's just a shrug and cynical minmaxing of funds to the shareholders. CGI 20 years ago was objectively worse but you can tell they had way to hide the flaws or redirect the eye away from them. Now... Ehh, who cares? Just get the first pass through.
If you want a relevant example: some people say Lili and Stitch's life action has a weird looking stitch model. Part of thst is because way back in 2005, the original Stitch was simply never meant to be looked at in a side profile for an extended time. Art directors made sure to avoid that angle in every frame they drew. 20 years later... meh. Ship it. Screw the outsourced CGI trying to model something better, the cinematography begin careful of angles, nor any reaction from "nitpickers". We got the IP, it'll make money.
It's not a franchise killer but it'd just one example of the many broken windows