These types of programs are great. I’m partial to this one: https://github.com/pn2200/g3data
I used g3data extensively during my PhD and have continued using it afterwards. You can see a significant fraction of the data I’ve transcribed here: https://github.com/btrettel/pipe-jet-breakup-data/tree/master/data
I think sharing transcribed data should be a bigger part of open science. Transcribing the data takes a lot of time so it would be best to minimize duplicate work if possible. I also note in README files if I noticed any issues with the data, though this could also be done on post-publication peer review websites like PubPeer. Putting the notice with the data is more convenient, I think, however. And if the problem I noticed prompted me to modify the data, that definitely is worth noting with the data. (I imagine that some people have a different philosophy where the data as published itself is an artifact that should not be changed, but I don’t share that philosophy.)
Also, if you want extra precision or find your hand shaking too much, look for a setting or program to do “mouse emulation”. This’ll allow you to move your cursor one pixel at a time with the keyboard.