Doping

do u even lactase persistence?

Yeah, but that occurred in completely different conditions to the present day, i.e. a much smaller population under greater stress, coupled with a new technology (herding) which made the mutation tremendously advantageous. That allowed a relatively small genetic mutation to be exploited to out-breed genetic lines lacking lactase-persistence. Modern humans are seldom isolated for long in small highly stressed groups where something substantial could evolve, and even when they are they promptly go on holiday and start fucking the locals and differences between populations get smoothed out.