Can I ask what software you ran into that issue with? Probably, it was a strict-monospace environment, like vim in a terminal. I have created code-specific fonts to deal with this issue:
there are fonts made specifically for code which have code ligatures & the simple l, f, 6, & 9 frozen in, if you like these features but don’t want to mess with OpenType features (or if your code editor doesn’t support that).
The issue doesn’t occur in web browsers, as far as I know, as they support proportional type (include mostly-mono families with a few proportional glyphs).
there are fonts made specifically for code which have code ligatures & the simple l, f, 6, & 9 frozen in, if you like these features but don’t want to mess with OpenType features (or if your code editor doesn’t support that).
https://github.com/arrowtype/recursive/tree/main/fonts/rec_m....
The issue doesn’t occur in web browsers, as far as I know, as they support proportional type (include mostly-mono families with a few proportional glyphs).