In an ideal world there would be sliders for scaling display sizes of fonts in EVERY application as we know them from Adobe and Microsoft products (leaving font point sizes intact). Just as we had on the old Evernote app for Android as Joungsoung has pointed out. That would be even better than iOS settings where scaling text can mean a jump from too small to too big. That’s what I experience on the Mail app, even with accessibility services turned on (offering me more steps for scaling – but I don’t want steps, I want 'infinite' percentage numbers in a slider…).
This may be a "minor issue" for Evernote developers as factus66 has suggested, but it’s enough to tempt me into moving all my stuff over to other apps: Outlook instead of Apple Mail (on the iPhone), Joplin instead of EN (on all devices). If only moving notes was as easy as changing mail clients… Joplin’s ENEX-importer does a pretty good job, though. Unfortunately, there’s no feasible way back to EN, which makes it a rather hard decision. Encryption of all notes is a fine feature, but it makes synchronisation over-complicated the way Joplin handles it.