Different customers value different things. In the list of things people value in their broadband, IPv6 doesn’t even register for for the majority. There are markets where you cannot even give away IPv6 connectivity.
Of those showing an interest in IPv6, many just want a static IP. If you give them one then you have solved their problems and are never heard from again.
If you really, really want IPv6 then you can usually get it in most markets. You might have to upgrade to business service or switch to an operator providing service over legacy copper facilities. That is, however, a bridge too far for almost everybody.
As an aside, you don’t indicate that you would pay a premium for IPv6 service. That’s not very enticing from a business perspective. If there was real demand for IPv6 or it could be provided for a premium that would change.
It’s a classical chicken and egg situation. No services require IPv6, so there is no demand for IPv6 and thus no IPv6 offerings either.
I’d be interested to hear why you highly value IPv6 connectivity, especially if you had a static IPv4 allocation.