So its not tracking you across instances? Then its probably tracking the invidious instance itself and not you in particular unless invidious leaks some amount of data about your browser which is possible.

If you don’t want YouTube to be able to develop a temporary profile from a single invidious session then I think you’re out of luck. Either make a new session per-video or give up. Invidious needs to pass YouTube’s bot management somehow and once it does YouTube will give it a trackable session token.

Are you always using the same invidious instance? Does it track across different invidious instances?

Its possible that is YouTube isn’t building a profile of the user but a profile of that specific invidious instance which is all of its users collectively. Its also possible that invidious is leaking some browser info like User-Agent to YouTube. That way switching IP doesn’t matter as long as its the same invidious instance.

Switching invidious instances should clear that up. If not then you’ve got a serious problem with invidious.

You just change it when you want to drop any profile you developed. ie on browser start. The problem with changing it every page is sites will assume you’re a bot and either block you or serve you a captcha on every page.

Browser Fingerprinting. You must configure your browser to lie about what it is and change the lie repeatedly. Simplest way is plugin to change your browsers User-Agent. This will be a big deal on mobile because mobile browsers will actually report the device model in the UA. Be prepared to see lots of captchas if you do this though.

The Gates Foundation had strong objections to releasing the covid-19 patents. I’m sure they had some sort of rationale that wasn’t "this would set a bad precedent for M$ patents.