Depends on the ROM. AOSP barely has any Google on it compared to "stock" Android; it uses Google services for system resources like DNS, time synchronization, c

Depends on the ROM. AOSP barely has any Google on it compared to "stock" Android; it uses Google services for system resources like DNS, time synchronization, cert stores updates, etc. This is configurable. Of course, it uses Google servers for updates. I believe that webviews and such use Google Safe Browsing. AOSP doesn't have Google Play Services at all. There's a trivial amount to "de-google". I'd recommend looking into GrapheneOS too once it gets 5a support.