Opera tried to make self-hosting mainstream back in 2009 with Opera Unite, but regular people just weren’t interested. It was a web server built in to the browser, which had a few apps like a whiteboard, a way to write notes, file transfers, etc.
Also, IPv6 is already mainstream in some countries. In the USA, several of the mobile networks are IPv6-only, using 464XLAT to allow connections to legacy IPv4-only servers. Comcast/Xfinity was also the first ISP to roll out IPv6 at a wide scale, and the majority of their customers had IPv6 connectivity way back in 2014 or so.
Globally, around 50% of traffic to Google and 60% of traffic to Facebook are using IPv6.