I think app designers perhaps had in mind touchscreen typers/writers on the iPad so the default font size was quite small and it was fitting for that. If one uses then a wireless keyboard though (which many are starting to use) my eyes are farther from the screen... even if I have my reading glasses with me, it is not that easy to read. Good contrast, brightness, AND bigger fonts are important if one wants to avoid eye strain. So I think, a bigger font is needed.
I tried Bear app, migrated all my notes (16000 of them!) And with all the tags included (not the notebooks which I don’t mind) it works! It is a lot better even, with adjustable fonts... As of now, the Bear app is my alternative. If no change happens on this (sounds like a threat, haha sorry), I will definitely migrate.