Every Invidious or Piped instance could easily implement IPv6 rotation, the smart-ipv6-rotator is fully FOSS and easy to set up. Invidious and Piped both have official documentation on how to set it up: docs.invidious.io/ipv6-rotator/
docs.piped.video/docs/self-hosting/#ipv6-rotator-…
Still works for me with a combination of Firefox, uBlock and a VPN. I assume sharing an IP with thousands of other people screws up their detection algorithm.