Accessibility feature: TalkBack (aka VoiceOver for Android)

Is your feature request related to a problem? Please describe.
AFAIK TalkBack is not part of AOSP and this I assume it is unfortunately part of the Google play services or so?
Custom ROMs do not have any accessibility feature for users with visual impairments or blind users, like at all. This is bad IMHO.

Describe the solution you'd like
Maybe it can be implemented in microG? Or at least a part of it?

Describe alternatives you've considered
I would guess one maybe could also try to install the official TalkBack app on Android. However, does that work? Judging Google, I bet it has dependencies to Google Play Services and if only for OCRing stuff or dunno.
Also, it would have to be installed as a system app or so to get access? Or no yeah you have this accessibility feature to get access to all screen elements but hmm?

Maybe I am wrong though, but I have not found any guides online.

Additional context
This is not listed on https://github.com/microg/GmsCore/wiki/Implementation-Status though.
My doubt continues though, maybe it really just works?

Start with the linked Implementation-Status wiki page and investigate whether the official TalkBack app works on custom ROMs without Google Play Services. The issue names no source file, test, or concrete implementation boundary, so completion would first require defining the supported scope and acceptance criteria.