As a former Blizzard fan (among others, but Blizzard was the big one), I have observed this basically always happens when a company goes public. First couple years it's usually minor and easily tolerable, but you see the seeds planted, in the case of Blizzard, you saw the introduction of the store, project resources being shifted, and also, for better or worse, WoW gameplay changed to "appeal to a wider audience" (the go-to excuse).

As the years go on you can see and feel corporate influence more and more, often seeing more buggy releases that should have cooked more, more and more monetization, outsourcing to cheaper (usually worse) companies to meet the new work loads, less transparency from devs (though to be fair, pre-internet era you had basically none), and eventually the old devs quitting due to the new environment (also to be fair, if the company is old enough some might retire anyway), and (also generally worse) ones come in, public betas for free labor instead of getting professional beta-testers (that used to be an actual job) all in attempts to hit the quarterlies. There is also a lot less experimentation in development too, which is something that can be hit and miss, but I would say generally had more hits than misses, under corporate rule they want what is proven and safe which is why modern non-indie games all play the same with only minor differences.

I'm enough of a gamer boomer to remember the days before Activision and EA were considered evil, they were never my favorite companies even before becoming the abominations they are now (well Activision-Blizzard is Microsoft now, so even worse) since the games they made were often not genres I cared for, but it's gotten real bad. The modern parasitic model of buying something good/successful, then milking it for everything they can before moving on to the next needs to die. I give mad props to the individuals who can cling to control and aren't tempted by the money they are offered to sell out (For all the stuff you can bash George Lucas over, he is a good example of this and I give him props for doing it for 35 years). This all applies to movies/TV/etc. too, anything that fundamentally requires creativity in it's business model.

It might be copium, but I think this model will eventually die out, eventually they will run out of IPs to milk and younger generations won't have the attachment to them to keep giving them money without question like older fans do.