There’s no need for it, apparently.
The next internet protocol should have stronger arguments, and perhaps start with being interoperable with IPv4.
IPv6 adoption is going to drag along, unless there is a compelling reason for people at large to adopt it.
There are reasons, but most of them don't apply to companies that either have enough v4 space or have enough budget to get the space they need.
As more consumer networks push towards v6 first/better, you'll see more hosting support v6 as an equal option rather than a second class option, but I don't think we're there yet. A lot of LTE networks do v6 as well or better than v4, but a lot of residential networks still don't do v6 or do it half-ass. A host doesn't lose a lot by being v4only, dualstack adds extra complexity, and v6only loses a lot of potential customers.
We don't need it because we can NAT.
We don't want it because we prefer privacy, not being easily tracked all over. Router walls over firewalls.
Multicasting didn't work out neither. No common ISP invested into more RAM for their routers just to stream a TV show more efficiently.
QoS contradicts the basic internet policies.
Personally I think the only realistic move is to advocate for an IPv7, which is backwards-compatible with IPv4 (keep ARP, keep classless addressing, keep DHCPv4, keep seeing NAT as acceptable, don't rely on multicast, etc.) instead of the wacky re-engineering project that IPv6 is. There's a clear need to get more addresses. There's not a clear need for all the other stuff being pushed as part of IPv6.