And? IPv6 is still under rather heavy development with significant changes still being made. As a user, I wouldn't call it well established because it's shifting too much still.
It's fine. The only breakages I've had are when the ISP's v4 DHCP goes down (v6 websites keep working) or when IPv6 delegation fails somehow and my machines lose v6 (v6 only stuff breaks).
Your mobile phone probably already uses IPv6 (especially if you use VoLTE) and it's fine, too.