IPv4 is a dialup slum.
Several factors contributed to the evolution of this slum with its associated slumlords:
As cable companies became ISPs and dialup ISPs became DSL ISPs, they adopted or retained the economic practices of dialup ISPs. In a world of megabit and gigabit always-connected homes, we still have the IPv4 characteristics of a dialup connection.
As Internet usage grew, the number of computers per ISP connection grew beyond 1. NAT solved both the IP resource restriction and OS insecurity problem. NAT has a significant cost though in that it protects internal machines by simply cutting them off from outside access.
In our dialup slum, we need third party centralized services just to send mail or send a file (as xkcd lampooned), make VoIP calls, or just chat with someone.
Before 1995, you could easily see whether your friend was logged into their computer. You could chat with them directly and send them a file directly via either email or ftp and not have to worry about which site to use, or whether they received it or not.
We're stuck in an dialup slum, paying rent to slumlord ISPs and websites. We don't have to live this way, though.