I'm using the volla phone x23 which runs vollaOS, an android fork without all those pesky Google background processes. It uses MicroG to simulate them though, since most Android apps expect them now.
Years ago I had a Samsung Galaxy Alpha and ran LineageOS on it but that just completely fucked the battery optimisation. Did this get better? Better than Google even?
My last phone with standard Google Android had a 5000 mAh battery while the new degoogled has one with a bit more than 6000 mAh I think. Even then I feel the overall increase in battery life cannot be explained with hardware only. Without watching videos or playing games, I only have to charge my new phone every 3-4 days. And I've background apps like syncthing running all the time.
I've just checked there's actually a few other open source forks of android other than LineageOS. If you're disappointed with it.
Degoogled as in "no code from google present" would require Ubuntu touch etc., but as in "no closed source stuff and no telemetry" is quite easy, using either Degoogled Android or another specific distro.
Does that mean no code written in google employees, or not using code written by google employees on company time, paid by the company? Because both are basically impossible.
As their contributions to the android kernel are also partly used in the main branch, you surely manually remove every commit of the kernel before building it manually, or do you use windows or mac?