The pain is most felt by the ISPs which need to supply lots of ip addresses to their customers, while you need only few ip addresses for running an internet ser

The pain is most felt by the ISPs which need to supply lots of ip addresses to their customers, while you need only few ip addresses for running an internet service (compared to the number of users/customers). There is little improvement in user experience and you need to change a lot of infrastructure to also support ipv6 addresses. So websites don't do it, sadly.