I don't think their map pool is shit though. People say this because they've been getting owned by Fnatic in EMEA most of the time. Their Ascent is good, Fracture is pretty good especially when they adapted to Neon, Breeze hasn't looked that good lately but historically they are good at it and they have all the qualities to be good on that map even with new comp, their Split is decent just like their Haven. Their Icebox is pretty meh, but so is OpTic's. And their Bind is again decent and somewhat different to other teams.
And the most important thing of this team is that every player can pop off. If they keep this individual form they don't even have to be amazing on some of the maps and they can still win. Its pretty similar to OpTic in that regard. Both teams individuals are just really good and can carry games. Also FPX is heavy antistrat team so they don't really have to have that strong map pool on paper. They can flex around if needed. For example just look how PRX kinda rolled OpTic on Haven with Sage and that is something FPX could play as well.
Also I think people are overrating OpTic's map pool little. They got rolled on Haven vs PRX, got rolled on Fracture vs PRX and DRX. And as I said their Icebox is usually just "yay go kill" and if that isn't happening they lose. And they aren't that amazing Split or Haven teams either especially when people have started to learn how they play.
so my prediction is that FPX wins 3 maps because I predict them to win, but the game is 50/50.