I work at a decent-sized ISP in Sweden, and we've been trying to get IPv6 to customers for over 10 years. It's hard. The way the Internet is built (many municipal broadband networks[0]) means there's middle networks that might not support IPv6 (the reason used to be "no interest" and "it's not a priority").

PTS is starting to show some interest[1], we'll see what leads to.

[0] https://en.wikipedia.org/wiki/Municipal_broadband

[1] https://www.pts.se/sv/dokument/rapporter/internet/2022/ipv6-...