As flawed as they were, I still managed to like XIII-2 and LR so I wouldn't mind a remaster collection. I still feel like they would have been better/more interesting as separate games not tied to each other.
I've gone back to Mobius full time after taken some months off and I'm still impressed with the content for the game, between the relatively easy farming of the premium currency in game and constant promotions you can rack up quite a bit of currency/tickets for the gatcha promotion of your choice just from daily logins if you take some long breaks.
The crystarium only affects the FFXIII regions anyway. And there is a story reason why Wol can use it.
They have lot of gameplay variations on a per region/event basis. Didn't you guys get the PuzzDra collaboration? That was the first one with gameplay variation (combos). The second FFVIIR collaboration, Fatal Calling, will have materia. Some of the later story chapters have element influence. The DQ collaboration has DQ jobs with their own levels, independent from your deck level.
Also, since some people still aren't aware, Toriyama has been directing Mobius from the beginning.