IPv6 became a draft standard in 1998, and did not officially lose the "draft" status until 2017.
Hurricane Electric launched their well-known IPv6 tunnel service in 2001.
Google has published IPv6 adoption stats since 2008. These stats consistently show a greater fraction of users are on IPv6 on the weekend, because it's more common on mobile and home networks than office networks.
http://google.com/ works fine for me, tested in Firefox and with curl -6. So it could actually be your side that is broken, although it is probably your ISP's.
My side works fine, Google just doesn't like the address. It's a tunnelbroker address, maybe they consider that bots... but only for some of their servers? It's weird