Central sever architecture is dominate because it’s easy. I can buy an IP address within a a data center and it will be routable. The lack of IPv4 addresses made giving every client on the internet an unique IP cost prohibitive for ISPs so we created NAT. The majority of clients who only connect to hosts are behind at least one NAT making them very difficult to address uniquely. The client must initiate a connection for an entry in NAT table to be added and allow for outside entry into the network. Further, more devices are mobile or on very dynamic IP systems that cause them to hop among many different IP address throughout the day or even hour. Trying to establish a connection to devices that have no static IP address is a problem that has no real elegant solutions but always defers to some known authority - the central server.

If we were to solve, once and for all, this ad-hoc, client-client connection system, P2P communication does require trust that many applications simply cannot tolerate. Game servers exist to validate client input, register actions, and distribute them to the players in the game, banking apps verify you are who you are and allow the movement or viewing of money, etc.

I don’t see a future where we fully leave the world of central servers behind but I do see one where we value P2P more and create public routing systems that enable this more freely.