Sorry if I don't conform to your idea of what a note should be.
Evernote's product specs clearly say "200 MB max. note size". Notes should not be unusable at less than 5% of that advertised size.
Notes aren't plain text. There is a lot of overhead. I just created a note with 1000 characters and the note info says 2 KB - 10 words - 1,000 characters. 2KB for 1000 characters, that's ~100% overhead. The note below has 2MB for 87K characters, that's 22X the size in overhead!
I'm seeing severe typing performance issues on a note that's 2 MB - 15,622 words - 87,627 characters. It has a lot of bullets. No images, just formatting. This one is horrible now for typing, large delays.
I had no typing performance issues until the most recent update(s). Something has clearly changed for the worst. I really suspect the expandable bullets with larger notes.