Ballpark estimate.
I want to be able to use my normie apps like a random calculator that requires 100% ram usage while it definitely doesn’t mine Bitcoin, wifi to display annoying ads and other obnoxious permissions.
I’m being more srs than I’d like.
Think I would still be able to use like 99% of my google play apps?
85-90% APKs/apps work independent of GMS or below dependencies/DRMs.
You precisely need 3 components out of GMS — Google Services Framework, SafetyNet basic pass, SafetyNet CTS check pass. microG fulfills the first one IIRC.
Out of the 10-15% that work improperly or without FCM reliant notifications, either a GSF sideload or microG should fulfill your needs.
Leaving all apps are the very, very handful and few apps that require either SafetyNet basic or full CTS certification, like Fortnite, Snapchat and so on.
SafetyNet is being phased out and could be replaced by hardware DRM or certification or efuse style hardware chips. https://www.androidpolice.com/safetynet-deprecated-for-play-integrity-api/