There's been some push from the other side: cell phones move too much in physical space to make IPv4 routing efficient (especially with today's scarcity) so today most cellular networks are IPv6 "native" and rely on IPv4-over-IPv6 router proxies for IPv4-only traffic.

Smartphones have been among the biggest leading adopters of IPv6 out of necessity to the network topology.

There already are IPv6 only servers and sensor networks.

On client connections most ISPs use DSLite these days.