[detaro]

Mobile networks especially are widely IPv6, with IPv4 being translated/tunneled where still needed. (End-user connections in general skew IPv6 in many places - it's observable how traffic patterns shift with people being at work vs at home. Corporate networks without IPv6 leading to more IPv4 traffic during the day, in the evening IPv6 from consumer connections takes over)

[stiray]

Android: Settings -> About (just checked mine, 10...*), check your IP. We have 3 providers in our country, all 3 are using ipv4 "lan" for phone connectivity, behind NAT and I am observing this situation around most of EU (Germany, Austria, Portugal, Italy, Spain, France, various providers).