I have a feeling its because they are open world / sandbox but no real feeling of "endgame" or replayability. They make you do the same dozen things 100 times each and the rewards are usually meaningless. Makes people feel like a glorified day job after a dozen hours.
The lack of decent coop or competitive mode make it a hard choice to want to buy right away, making stores drop prices to move dusty copies.
I am not saying single player is bad, or open world by any means, but when you just copypaste the same missions all over the map it feels like work.
Ubi games have become super derivative, it’s similar to the COD seasonal model, or really any franchise that uses an established framework and tweaks it each year.
I’ve preordered almost all of their next gen releases to lock in lower prices, especially if the $69 next gen trend gets legs, but I’ll probably only end up keeping one. And even that one (Immortals Fenyx Rising) looks like it might be too similar to Odyssey with design changes. They’re like the fast food of games ... tasty in small quantities but not great quality and not the best games you can buy.