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.
Even more glaring is TV shows, where you now get an 8-episode 'season' every 2-3 years rather than the old days of 20+ episode seasons every year, often non-stop for 5 or more years.
It's not so much about capability/competence as pushing production values to unsustainable levels. You could get away with much less expensive VFX, sets, and costume when filming in standard definition. Now every pixel is expected to look flawless at 4K.
Another more controversial factor is that everyone brings their politics/activism to work and injects them into everything that they do. Now everything has to be pushing for social change, nothing can just be entertainment for the sake of entertainment.