My guess is that average is better but NA's peak is higher is because in EU they have more exciting games, i don't mean better teams etc, just look at VCT for NA VS EU, IN NA group 1 u got basically a guarantee that either EG and LG are dropping out or 100T's and EG are dropping out, There isn't anything in it same with group 2 there, Either Knights and NRG drop or Rise cause an upset and lose out.
Look at EU now
U have TL throwing pretty hard considering they got top spots last vct, Then u have Navi and FPX Completely coming from nowhere and maybe qualifying, in group 2 u have Guild absolutely destroying when they weren't even expecting to really be in the running for VCT.
There's more teams which are bigger in EU which are losing and causing upsets, while in NA the groups are going basically as planned, There's more hype around EU, That simple