It is not an abuse to use a font to provide icons. What are letters, if not icons, after all! :)

Letters and punctuation are not icons at all. They are symbols. Icons are images, i.e. likenesses of concrete or abstract objects which they refer to. Letters have no meaning on their own, they represent sounds, which differ based on language (e.g. c sound like see, chee, key, gee, that &c in different languages) or its position in a word (caps, ace, click).

And if its not an abuse of fonts to use them as icon packs, its an abuse of the users who wants to use their bandwidth for better things (e.g. cat gifs). I have them disabled and my day is full of fun: What this "f" means? What happens when I click "ff" or "p" or what not? And some are kind enough to provide alt texts, which is soooo helpful: https://imgur.com/cHdSxcO

Okay, I was being a bit facetious, I admit :)

In practice I don't consider it an anti-pattern to include icons in fonts. Fonts are designed in such a way that they're pretty convenient to use for icons.

There are of course other approaches now available, and they should probably be used preferentially. But it's much like complaining here that you have blocked images, and therefore can't see any images. It's your choice, and I'm glad you have it, but…

I'm curious what benefits would be evident while using a font that also combines icons in its character space. I can only imagine slight drawbacks.

I feel like this is a bad trade... let me break every website I visit, so I don't have to download Font Awesome and Material Icons?

Why would you do that to yourself? What's the benefit? A couple KB?

Letters are not icons.

"Letters are things, not pictures of things." -- Eric Gill

Github did a great writeup on the perils of using fonts for icons. One reason was the one mentioned here, users overriding them with their own preferred fonts.

https://github.com/blog/2112-delivering-octicons-with-svg

I think the issue is less about philosophy and more about technology.

SVG icons are better than icon fonts in pretty much every way. The only example I can think of where an SVG could be considered worse is if the icon is particularly complex. Even then, the only thing that is worse is file size. At that point, a PNG is probably better, anyway.

Don't get me wrong, SVG is better now, though sometimes I fall back to using an icon font because it's still a bit more straightforward. We'll get there, though.

No, SVG is not better than a font for monochromatic icons and never will be.

The amount of optimization that went into font technology and algorithms, all the way from the binary file to the graphics card, can never compare with an XML-based file format.

There are more benefits to be had than time for a browser to render an image.