Equity PM compensation: EU vs US

just wondering, how come that in the US PMs get paid way more than their counterparts in the EU with equal assets/ firms/experience? i mean most of the guys here (who are certified professional) seem to agree that, for example, a PM at Fidelity, US based, with ~800mil in assets and with lots of experience will make north of 500k dollars per year bonus included while looking a little bit on the internet (some surveys or conversations) it seems that a PM, EU based (that is London), with similar assets and experience will make 120-140k euros (or ~100-120k pounds) which in a way seems unfair. [yes i know there is FX to be accounted but overall if you work in the EU you will use pounds or euros, not dollars to buy goods and services)

now, given that i don't think that all of US PMs are overperforming versus the EU PMs, could someone please explain this discepancy? is that i have wrong data (namely AUM and comparable experience)? or that regulators here are more aggressive in limiting compensation?

thank you very much for your time!