First of all, Europe is no monolithic entity. The cultural gulf between Portugal and Latvia is massive.Europe tends to be more accepting with teenagers dating 20-somethings, some people may raise an eyebrow or two, but nothing out of ordinary.
As an example, mr. President de la France, who began dating his teacher, 24 years his senior when he was 15-16 years old:
Secondly, "Europe" is no more accepting of it than the US. 16 and 29, give or take, may not be illegal but it's still not sth many will look approvingly on.
And finally, your example of it somehow being more accepted because "look at Macron" simply doesn't work at all. I have literally never heard of anything even remotely similar happening here. His personal history has never stopped being extremely weird. It's just that at this point they are both consenting adults, and certainly the one difference between you and us is that we don't tend to care much about our politicians' private lives so long as there is nothing heinous (and illegal) going on there.