@mwl not a single polish GSM carrier does IPv6 by default. At least two of them do only for business contracts. The situation with residential ISPs isn’t much better, with one (UPC/Play) offering a selection between IPv6 + tunneling IPv4 to one IP half a country away or just native IPv4, and several others offering IPv6 (but turning it on breaks IPTV/telephony on their default config).

I hecking wish my phone did IPv6 - outside my wireguard tunnel, at least.