[Quoth]

I just tried on Android.
An earlier Android was like a bad version of Voiceview and very hard to use, also took over entire UI and hard to disable.
Android (10) on the Lenovo Yoga 10" Tablet (about €220 or less) was simple in Settings, Accessibility:
Download desired Google speech pack
Switch off reporting to Google.
Select voice, speed and pitch in settings (except preview of pitch doesn't work).
Enable an Accessibility option, a stick figure joins the <| O [-] symbols
Open An ereader App (I tried lithium) and a Media controller pops up when stick figure tapped. Not tried in Kindle App.

The older Android was unusable and navigation entire system was locked to voice prompts and it only seemed to read part of page tapped on. Useless to listen to a book via TTS. Worse than my testing of Voice View on Kindle PW3, which is also rubbish for simple TTS compared to Kindle DXG or KK3.

If no-one tries, I may try Bolinda Borrow box (our local libraries instead of hoopla or libby), Google Play books and Kindle App. I've nothing in the Kobo app.

I have an eink Mars (Android) but I don't remember TTS on it, but a phone (earphone) or tablet (speakers) maybe better. I have some other versions of Android I can try.

Edit See below