Probably part of the reason so many large game companies have been turning out titles that are either lackluster or get flambe'd by gamer feedback is decisions forced on the devs by the "number crunchers" who's only goal is to try and squeeze every penny/schilling/rupee/etc... out of the industry and have no interest in the actual industry itself or quality of the products produced by it. This results in bad design changes, dropped features, and unfinished releases as the "number crunchers" attempt to manipulate the company's quarterly earnings reports. In some ways thinking back these occurrences might have escalated after No Man's Sky. That title officially launched missing a huge amount of things the devs had stated would be in the game resulting in a horrifically bad launch. However Hello Games did commit to sticking with the title and eventually fulfilling the content promises and more and it's become one of the best ongoing games currently available. Seeing this might have triggered a mindset in many that it's OK to release a game in a poor or unfinished state as long as they patch it up later. Of course you also have Bethesda who has a long standing reputation of releasing titles flooded immensely with bugs and glitches that range from humorous to gamebreaking but still managed to stay around.
As for FF16 sales not meeting expectations. Blaming "lack of PS5 availability" is nothing but an excuse. The running trends of AAA game releases has resulted in people being far more reluctant to preorder a title. Thus they wait for the title to release and more information about how it plays becomes available from actual gamers playing the game rather from "gaming journalists" giving reviews. When people could clearly see that FF16 was not the next gen FF game they were looking for, they chose not to purchase it. Hence the sales tanking heavily after the first week.