The enshittification of the internet follows a predictable trajectory: first, platforms are good to their users; then they abuse their users to make things better for their business customers; finally, they abuse those business customers to claw back all the value for themselves. Then, they die. It doesn't have to be this way. Enshittification occurs when companies gobble each other up in an orgy of mergers and acquisitions, reducing the internet to "five giant websites filled with screenshots of text from the other four" (credit to Tom Eastman!), which lets them endlessly tweak their back-ends to continue to shift value from users and business-customers to themselves. The government gets in on the act by banning tweaking by users - reverse-engineering, scraping, bots and other user-side self-help measures - leaving users helpless before the march of enshittification. We don't have to accept this! Disenshittifying the internet will require antitrust, limits on corporate tweaking - through privacy laws and other protections - and aggressive self-help measures from alternative app stores to ad blockers and beyond!
If someone wants to host something, NAT won't stop them. IMO the bigger problem is that most folks have neither time, skill, nor interest to make p2p a reality. I'm a pretty savvy admin, host a lot of services for myself and family, but I don't pretend to be good enough or vigilant enough to run anything public, i.e. mail server, lemmy server, etc, without major security concerns.
Part of it is the war between security and privacy vs open architecture. The moment you leave your car unlocked some creep will rob you.