Neanderthals became extinct what some 50,000 years ago?
That is only about 2000 generations.
And since Neanderthals are known to have mixed with “modern humans”, many people still carry their genes. Actually observing behavior of some people, it is quite obvious hahaha.
Terming Neanderthals “extinct” may be as erroneous as saying that certain native American tribes are extinct. In that instance, there was no extinction, they merged into a new population via interbreeding and ceased being distinct due to genetic swamping. That’s a far cry from extinct, which carries connotation of being killed off or dying out rather than being bred into a hybrid.