> what kind of p2p protocols are you thinking of ?

Skype was originally P2P, but because of NAT there had to exist "supernodes" which did STUN/TURN/ICE shenanigans to make it work (which caused scaling issues since there weren't enough of them):

* https://spectrum.ieee.org/skype-scuppered-by-problem-with-su...

* https://www.zdnet.com/article/skype-ditched-peer-to-peer-sup...