@Tubsta IMHO, IPv6-only ISP would not be useful in the US for at least several years. There are still a lot of IPv4-only residential and small business services that would be inaccessible without 6to4 NAT, and at least some people with IPv4-only access might not be able to reach the IPv6 network reliably.
I only have IPv6 because of the free Hurricane Electric Tunnelbroker service, but it takes effort to set up a usable dual stack internet connection. My ISP has zero plans for IPv6. There is little consumer demand for it, probably because NAT (or "CGNAT") fills the gap well enough for most consumers. it would require staff and consumer training, network redesign, systems testing, etc., all for no additional income
OTOH, an IPv6-only server may be viable for the right group.
at one point I considered starting a social network only accessible via IPv6, DNSSEC, and with X.509 client certs.
Because "f*** you, we need to move forward, that's why."