I think one big reason why IPv6 won’t be a thing for a long time is because to the people involved decided to do away with NAT in IPv6.

What a huge mistake.

NAT is obviously a huge crutch but everyone uses it because it’s a dead-simple firewall and makes for dead-simple internal networks. There are NAT-inspired IPv6 analogues but they are not the same.

If NAT with IPv6 was a thing, ISPs could have started shipping routers to customers (as they already do) with IPv6 turned on and we would have already been most of the way to IPv6.

But no, they felt NAT was too hacky and did away with it on a matter of principle.