Not an issue if you already have an ipv4 address
I guess that the basic issue is that for most people, IPV4 just works, and all their devices are behind NAT.
I stuck IPV6 support into the products I support some years ago, and from the occasional customer logs I see, it seems to be a thing, but that's all. Also, you can't really use it without a DNS; the addresses are impossible.
So who is going to volunteer for that?