Emacs does provide that

Emacs + Eww + custom elisp code to launch external tools for unsopported sites it's far lighter than this.

How do you mean? Like supporting emojis?

I mean normal text being rendered with a variable-width font instead of as monospace, for better readability. When I was younger I didn’t care much, but as my eyesight is getting worse, monospace text is becoming more straining to read.

Rendering variable-width fonts in a TUI-like layout environment isn’t exactly straightforward obviously, but I’m sure it could be solved adequately. The point is to still retain the snappiness of TUIs by not going full GUI and by still limiting layout to the coarse textmode grid.

I'm imagining programming Python using a variable-width font and that makes my head hurt. :)

Oh yes, that makes sense. I wonder if anybody's ever attempted that before