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.
So alot unfortunately is a choice that consumers have made. Even in terms of media again, alot of modern viewers watch media more as self-insert fantasies, so quality of writing or novelty is often going to worthless or even detrimental to them. I don't believe that mindset, but having talked to many on /a/, /v/ or reddit, there's many who are just there to consume rather than actual interest.
Your average gacha may look lower effort, but it has to sustain thst effort longer instead of patching the game for a few months and moving on. It has to do a lot more marketing to get players in, because many are this pseudo-MMO experience, completely with PvP and Guild content to manage.
At the highest end, Hoyovervese's operating costs would even make Activision blush. But those games make billions to compensate.
That very much is an indictment of ambition and progress here.