

I’m not sure how to word this differently other then again saying that the Invidious popular tab should be the same for all your devices, all my devices, and everyone’s devices since the base Invidious is open source, claims to not track its users, and the popular page is built from what everyone on that instance watches.
The entire point of Invidious is to completely remove the direct google connections when users watch videos so assuming your instance is not some kind of google honeypot… for almost all intents and purposes google cannot track you when you use Invidious especially if you’re on a secure browser behind a vpn and if they could they would not reveal their hand to you in such an obvious mundane way. Most websites are made for people not actively trying to avoid tracking so just hitting the private browsing or incognito buttons is almost always enough to make that kind of obvious tracking go away even if the underlying server or a chrome browser phoning home is still 100% confident of your identity.
Again: google tracking you should have nothing to do with invidious and once you’ve change IP + fingerprint your anonymized setup will share no direct links with your previous setups so no site would be sure enough of your identity to sync video recommendations. It’s not just what I am saying, it’s a fundamental truth of how the internet works.
Google can only track you with the data you give or allow them to have. A lot of people report their android phones as listening to them and some stuff has come out about that so there exists some chance that your youtube recommendations on youtube could be influenced by one of your devices being able to physically hear the audio of invidious videos you watch coming out of another device’s speakers… but that’s supposed to only influence ads and you say you use ios so it’d be very unlikely.
The most likely scenario is that your initial conclusions are flawed and in actuality you are being affected by things like confirmation bias. Please look for actual evidence of a device that is not yours using a fresh anonymized setup showing different results from one of your devices with an anonymized setup. Again, the Invidous popular tab should be the same for everyone but based on your words you still seem to think that it being the same despite your efforts means that google is somehow tracking you and is somehow using their tracking data to inject video recommendations into a site they don’t control which would basically be impossible on multiple levels because things just don’t work that way.
Avoiding google is one of the hardest privacy hurdles because they own and control so much of the infrastructure that many people’s internet lives rely on. Other bad guys won’t have the same access to google’s infrastructure so it’s not safe to they can too. And it’s very likely that all of them won’t be following you after you’ve anonymized your setup and will make no attempts to do so unless some sort of three letter agency is actually after you specifically.