> Just don't rely on centralized for-profit entities, rely on stuff produced by non-profits and foundations, that you know isn't gonna screw you over as soon as they need money

What do you use that fits that philosophy and offers the basic functionality (NAT traversal, Magic DNS, failover relaying) TS provides?

Nebula has NAT traversal and failover relaying I beleve, but not magic dns

This is correct, and the lack of a MagicDNS solution is definitely felt when using Nebula (esp. when switching from Tailscale)