Do they serve you ads today when you have a paid subscription?
If they ever start doing that, you could stop paying. But not paying now for the hypothetical possibility that they may start serving you ads in the future sounds more like an excuse.
YouTube doesn't, but many video creators do. Not something YouTube has much control on though, for them, that's just content and is served as such. You can use the SponsorBlock extensions to automatically skip these if you want.
Right, but the claim was “GOOGLE wants you to watch ads AND pay for a subscription” and that doesn't seem to be supported by the evidence.
I get that as a premium subscriber you still see in-stream sponsored content, but that's because the creator wants that, not Google. I think Google would rather have those sponsored messages be run as regular Youtube ads instead, so they can take their 45% (?) cut of the ad revenue while letting premium subscribers skip them.
If they ever start doing that, you could stop paying. But not paying now for the hypothetical possibility that they may start serving you ads in the future sounds more like an excuse.