This isn't necessary a critique of these pictured films (and one tv show) regardless of how anyone else feels about them, just an observation I find curious
I mean the obvious answer for at least one of them is that Ridley Scott wants to talk more about androids now but ended up having the Xenomorphs shoehorned in again in Covenant but I feel we must be past that now.
If I were to play conspiracy theorist, I do wonder if another reason for this is that Alien 3 is such a divisive movie in the franchise and the death of Ripley and her new found family is a sore spot that their kind of "umming and ahing" the canonicity of it
Especially with stuff like the cancelled Blomkamp Aliens 5 that would have retconned her into surviving or the dubiously canon 'Colonial Marines' video game DLC where Hicks corpse was actually a body double and he's still alive, as if writers don't want to tread on each others toes.
But I don't see why we can't have stories set in that time period that just stay clear away from Ripley's side of things. The video games still do at least, Dark Decent (not the Amnesia game) Fireteam Elite, that freakin' last AVP from a decade ago now. Maybe it doesn't really matter to much but I'd be curious to explore a universe that has more experience and knowledge of the Xenomorphs and what could be done with it
although I don't blame them for not wanting to look into Resurrection's big time skip again unless anyone else is curious