I use the NoScript extension so I can pick and choose what javascript runs on my browser, and that's how I noticed this.
When I open a link in any Invidious instance, in addition to the instance's script it also wants to load a script for "googlevideo.com" (see pic, if I attached it correctly). The video does not load unless googlevideo.com is flagged as "trusted" for NoScript.
However, loading the same video in any Piped instance only loads the piped instance's script. NoScript doesn't note any additional script.
What's going on here? Is this a problem?
For a sample comparison, here's the same YT ("Chickens Play Football With Corn on the Cob", 47 seconds) in an Invidious and a Piped instance:
Most instances, by default, only prevents sending the telemetry. For complete anonymity (against google) change the settings to proxy the videos. This will prevent google from knowing your IP. Some instances turn off proxying settings permanently to avoid massive bandwidth usage.
So if I selfhost an instance the proxy setting still would hit my hosted ip?
if you host that instance on your own ip, yeah.