For me it's got very limited use, if at all. My primary browser is Firefox with ublock, multi-containers etc. but Private Relay won't work with it. Also, my home network has a Pi-Hole and I have to manually change my DNS to a public one if I want to enable Private Relay. So for a privacy use case, with browser fingerprinting and all, there's the tradeoff that you can hide your IP but have to give up on the Pi-Hole protection. All ads start showing up in Safari. I'd rather go with a VPN that tunnels all computer traffic except DNS. FWIW, this is my poor man's VPN with a free Google Cloud micro instance used as a socks proxy with Firefox:

  ssh user@IP -N -C -q -f -D 1234