There are a lot of reasons for this, some are Ubisoft's management team sticking their heads in the sand, and some of it feels like the inevitable end of the road for many other publishers. Game budgets spiraling out of control, rising borrowing costs, and decreasing public interest in your franchise. I know it's a meme to criticize Ubisoft for disbanding the POP team, but it's pretty clear now there's no money left to fund a new project for them. Seems like purely a business decision, and a desperate one at that.
When it takes this many large failures to bankrupt a company like Ubisoft, just think about how risky it is for a smaller publisher to create something even close to AAA. Not saying Ubisoft has been making quality games that last several years, but this isn't good for the industry. Take one look at Zenimax, then Activision-Blizzard, and now Ubisoft. We are headed into consolidation of the industry into a few large players who happen to own existing platforms. Even first party publishers are being pressured to expand their audience and move to multiplatform releases. It seems by the end of this generation, the only platform exclusives are going to be based on specs alone and a few high profile first party releases.
This is terrible for competition and terrible for gamers. And it's a shame, because it has been a fantastic time to be a gamer - from 2017 to now, I don't think there has ever been such a quantity of well made games of all genres.