Well, /e/ OS ‘Q’ is a fork of LineageOS 17.1. LOS 17.1 is based on AOSP Android 10. The fact that /e/ makes some changes to the code does not justify saying it is not based on AOSP Android 10.
Without Google, this AOSP Android would not exist. AOSP stands for Android Open Source Project and is only a more specific name for the mobile operating system.
The term “AOSP based” is used when the Android in question is only slightly adapted. The open source stands for the source code of Android, which contains only the necessary and useful codes.
This version is offered by Google for download free of charge. This means that every developer can experiment with the basic structure of Android himself and make carry out adjustments. Manufacturers and developers are very free here and there are only special restrictions that affect Google services.
For me it makes really no sense to write LOS or AOSP based in the head line of such post. I will stop here, because it’s running out of topic and I don’t want blocked again.