It’s the capitalist pressure to constantly be hitting those quarterly profit goals. These AAA studios are typically part of larger tech/media conglomerates whose shareholders want to see those steady profit streams and so they stick to these release schedules even if the game needed another six months to a year in the oven. And the gamers have made it clear they’ll eat up the slop regardless so there’s no real pushback.

It’s interesting that you mention From Software as an exception as the other company that comes to mind like that is another Japanese company, Nintendo (who of course have their own problems and sometimes suffer from that issue). Apparently on the new Mario Wonder game, corporate gave the devs no deadline to complete it, just “work on it until you think it’s release ready.” Might be a different attitude with CEOs/board members over there.