If you have the original Google WiFi pucks, I have recently flashed them with OpenWrt and it has been great.

Took a bit of time to fully set them up properly, got locked out and had to reset them multiple times. But am super happy with what I have now. Running multiple VLANs, a real firewall and the WiFi seems much better.

The internet itself is shared. If that’s the case, put a router in and you are protected as with any ISP.