AFAIK for desktop-client it works. But there I have a mouse.
Select a part of text with my fingers is always dalliance.
I don’t need very often only a part of text copied. If I need it, I copy the whole text and delete the not needed part by using the backspace button.
So more important would be contextual reply.
https://support.delta.chat/t/reply-to-message/283
This is the most case where I use copy and paste.