I don't use google accounts on my android phone. And yeah like you say whatever access they still have (not so much IMO) they have anyway regardless of which messenger I use. And yeah I do mind having facebook involved but it's just not really avoidable where I live. I really need whatsapp.

I do however have one mitigation: I don't run the whatsapp app on my primary phone. I use a matrix bridge. The app is still installed on another phone which is left at home. Because every month or so you have to enter the pin code (apparently meta thinks us users are retards that will forget it if we don't keep entering it).

On my phone I use the ElementX app then. I did get banned from whatsapp one time which was presumably to do with the bridge (I don't see what else it would be).