That’s not accurate. The eyestrain comes from staring at the same thing for too long without your eyes refocusing every now and again. On top of that people stop blinking as much as they should. You get just as much eyestrain from reading books as you get from staring at a dark or white screen if everything else stays the same (time you stare, how much you blink).
I love FOSS and hate myself for doing this but personally I gave up on the idea of forcing myself to using a worse FOSS app over one that just get’s “shit done”.
Convenience in the gym is the most important imo.
Hevy is a great app even without paying. Take that for what you will.