Depends on the perspective. It could have been pretty big if he managed to carry PSG to their 1st CL title but I agree that in terms of international prestige, Ligue 1 is clearly behind PL, liga, BL or Serie A (even if serie A is overrated imo). That's the problem with PSG, if we screw up in CL, the rest is pretty meaningless for most people, no matter how well Neymar plays (and when he's fit he's probably the best player i've ever seen wearing our jersey, even better than Ronaldinho).
His main issue was the injuries that kept him out of the pitch for the past 2 years, because it was his only chance to really shine at an international level.