For me, I think proportional fonts are the way text was meant to seen, and monospaced fonts exist to accommodate the limitations of computers, printers and typewriters.
Why is that? In text or punctuation?
For words it’s more readable. The punctuation is designed for coding. The numerals are still monospaced.
I would love to use a proportional font for coding but I am not aware of any Vim frontends that cleanly support it. I would be fine to stick with using monospace when using Vim over SSH but even though Neovim has opened the floodgates to frontends it seems that very few support proportional fonts (and the ones that do tend to be painfully slow to use).
I have recommended this many times here, but I use a proportional coding font: Input Sans
https://input.djr.com