[AceJohnny2]

> Also, damn every ISP and every router company that doesn't 100% support IPv6.

It's extra development and extra testing (in fact it's way more testing due to the combinatorial explosion of IPv4/IPv6 interface schemes).

That comes at a cost.

> ISPs and endpoint network devices are the only reason we don't have IPv6 more prevalent, combined with NAT, CGNAT etc. being good enough to keep the net hobbling along.

ISPs & endpoint devices are the majority of the Internet, as far as complexity is concerned. Upgrading the equipment for HW-acceleration of IPv6 (parity with IPv4) is very costly.