Megalodons are extinct because they were not deep-sea dwellers and their extinction is evidenced by the subsequent change in whale evolution and body size.

“it's not like they were living in the deep ocean that that was not the case it's not like oh they could be down deep in marianas trench and we could drill them up actually no they didn't live that deep that's not a thing that was happening also the the biggest way that you can tell is by the size of”