I only occasionally need support from screen reader software (my vision is bad but mostly correctable, but sometimes I can't use correction due to other medical issues. Eyes suck.) and I've been testing Piper + Orca lately.
I recommend the resources linked above.
Actually, I wrote a short tutorial about it that should be published next month - I'm happy to send over an early copy if it would be useful.
Orca, the standard Gnome screenreader, by default uses standard eSpeak voices.
I find these really grating, while Piper's neural voices are much more pleasant, particularly for listening to long passages of text if you're not very accustomed to eSpeak voices.
However, Piper has some practical limitations. Notably, it's more processor intensive, which becomes more conspicuous on less powerful hardware. (It''s okay on an aarch64 Raspberry Pi 5, but I'd not go much below that in terms of spec).
Also, while eSpeak can keep up with a fast typist (in its way), Piper isn't great for letter repetition. This becomes particularly conspicuous at the terminal.
Your friend my also appreciate Speech Note, which is handy for partially sighted people who don't need a full time screen reader, as you can just paste in text to have it read to you using Piper voices (or others)