How to get rid of GMS (Google Mobile Services) issues on de-Googled devices?

Recently I've decided to de-Google my phone, and noticed some issues: 1. GMS is NOT the core of AOSP, BUT is definitely required for most apps that need some account management to work properly like all Google apps and most third-party apps that I can easily live without or replace with other apps. 2. The lack of Google Play Services drastically slows down some of the basic apps like browsers (not all of them, but most like Chrome, Edge & Brave), although I can use browsers or alternatives for things like synced calendars, notes, and office. I currently have no idea how could I make the basics work flawlessly with GMS completely removed. Any recommendations?