Challenge ratings.... most of the creatures so far in game have a 0 or 1/4 challenge rating. Anyone who says level 10 is fine is deluded or never played bg II.
Here's a little comparison for you as to how terribly bad level 10 for the third game in the series is.
https://baldursgate.fandom.com/wiki/Experience_TablesI have always hated the idea that lcl 10 is the end. BUT we live in a world where DLCs are the way to go and i can't imagine a game this big will end without at least having one or 2 of them. So maybe they add more levels with those...who knows.