I find monospace fonts surprisingly readable, but the font size is too small on smartphones, and yeah, the alignment is off.

We’re in 2023. Use reader mode.

And where does 'getting downvoted' fall on that list?

For programming, correct.

But long form essays - it's super difficult.

Braille Institute is an authority research group in this space and they development their own font that achieves maximum readability.

That font is NOT a monospace font, because the found it too difficult to read in long-form. It's a proportional font.

https://brailleinstitute.org/freefont

That font seems to be designed for low vision readers. I'm not sure if you can extrapolate that to people without any sort of vision issues. I mean, I can read the essay just fine, and I don't find it particularly hard to read or anything. If anything, given that I'm already used to reading monospaced fonts all day, I think I can probably read it faster than if it was a font that I'm less familiar with.