I’d say raid based tasks are fair game, they’re arguably the most underrepresented in tasks outside the L40+ “research” and yet they have, I think, the most potential for variety and challenges. There’s essentially a PvP based one every season if you count getting the ETMs, plus “win X battles” are creeping in there more often. The “win X raids” tasks are meaningless, as you can just pile 20 deep into some remote raid with any old team and yay, you win!!!. GBL at least you’re matched to your level.
Niantic have even shown that there is some in-game acknowledgement of intuitive difficulty level when they made some of the rockets scale accordingly. Surely this could be worked into other areas so, say, “solo a T3” was doable by anyone, but with some thought as to your team?
I get that PvE is the poor relation now you can get your Legendaries and RC from PvP for free but for me, there could be some balance in there that keeps everyone happy, to some degree.
You could balance it by having “win 3/5” of a GBL set or “win RC or three encounters from GBL” perhaps?
I liked an earlier idea of having, say, 5 tasks but you only need to do 3 or 4 of them. That way, if you hate GBL you can raid more and vice-versa. I think what I’ve realised from this as well is that, having started as a social exploring game, more and more it’s turned to a battle online opponents blindly game. I know it won’t happen but some way to share online messages with your opponents or raid buddies would really improve that aspect again. There’s about 4 or 5 people on my friends list I’d really like to chat to, even just to say “thanks for not bailing every time there’s less than 15 people in a raid”.
Anyway, I digress, as ever, it appears there’s likely no way to please anyone and nor do niantic care beyond any massive backlash which has happened maybe 3 times in the history of the game.