I have a TBX file that I keep quotations in. With iOS 15’s Live Text feature, if I’m reading something that seems like it might be worth remembering or sharing, I can use my phone to grab that text, save it into a note in Apple Notes, and it’ll appear in my Quotations TBX.
With Live Text, if the the recognizer only includes the text you want to save, you don’t need to “Select all,” just go right to Share. Even if it contains more text than you want, I’ve found it easier to just share the whole thing to a note, and edit/delete extraneous text there than on the camera screen, where a stray touch can make you start all over.