But recently, I've found everything I need in UTF-8.
And the result is a huge reduction of the size of my asset bundle for my web applications.
Then, I must ask the question, why are those libraries so wide spread ?
I know you could technically "look it up" but to get "reasonable" coverage I believe you would really need to stick with system/standard fonts.
As an example:
System fonts on major platforms typically support thousands of glyphs (but each is free to specify how) and while the intersections are bound to be almost complete, there are also differences.
This pales in comparison to most custom fonts such as those offered by Google and Adobe. Google's Roboto offers only about 300 glyphs and those are almost exclusively traditional "characters" not emoji or symbols.
With an "icon library" you know what you are getting and typically in a format that is standard across platforms.
Yet, if I use only one or two icons from a library that weights near 10MB (Font Awesome Free is 8MB), when those icons are available as UTF-8 glyphs, is it still unreasonable ?