While I'm also asking for myself, I'm currently running Lineage OS with no Google apps or services, but eventually I think I'll be forced off of an Android-based system entirely.
Besides installing malware on devices with Google Play services, Google is also doing things like making AOSP less frequent updates and stuff like that too. Eventually, I'm figuring I'm just going to have to leave and go to a Linux phone entirely, whether I want to or not.
For me personally, the things that I absolutely need to work are the touchscreen, calling, texting, cellular data, microphone, speaker, bluetooth, and Wi-Fi.