Ubisoft has been struggling with a lack of good leadership. Now news has surfaced that dealing with Epic has not panned out as expected. Xbox has no problems with Steam and they sold a vast number of games.
Ubisoft created their own loader and store but sales have been lackluster in the extreme. Part of the problem is that besides Division 2, their portfolio is mediocre at best. Today Division 2 has a 5.55 GB update suggesting some additional maps are being added. Being third person is hard for a guy who usually plays first person shooters all day. The gameplay is different enough to be alien.
EA has lost as lot of games from the Origin loader back to Steam. Lot of people were not happy when GameSpy folded and EA did not fix the problem of game servers. Today EA now offers games on Steam with only a few they are still tied to Origin.
It remains to be seen if the management over at Ubisoft will consider returning back to Steam.