These crazy outdated licenses that let you print as many magazines or books you want forever, for a one-time price. But if your hobby is making apps, then suddenly the same font will cost you 50 times more - for a single year.
I guess these font sellers imagine there’s still some app boom - a Klondike rush with developers bathing in dollars. Maybe if their licenses were more realistic, piracy would be less of a problem.
I'd argue that complaining about font prices is less like a Hermes bag, and more like complaining about high-end ingredients when a supermarket has cheap stuff. Yes, you can get away with cheaper materials when cooking, but the final product will deeply suffer.
You may not care about fonts, but to say they don't matter is a misunderstanding. For example, I could glibly say we only need one programming language (the user doesn't care what syntax you used before it was compiled down to 1s and 0s!), but any engineer would make the case why that's not true at all.
Programming language choice has an aesthetic side, but it is also very much a functional concern. Can I write secure code? Will it be performant? Will it be maintainable?
Different languages represent different functional tradeoffs. Are fonts really the same kind of thing? IOW, how would you make a choice between using Arial vs. Helvetica?
But just because those two typefaces are quite similar (and the reason to pick between them is largely financial/convenience) doesn't mean you'd never want to have more fine-grained control over the text you're working with.
You mentioned security. When I'm editing this comment, 0 and O are very different (the zero has a slash through it), however when I hit save they look quite similar. (But because we're all using system fonts on HN, it might be different for you). While it's often just a stylistic choice, in many situations the two characters would be indistinguishable and that would be an issue, which is why someone might choose a typeface where characters are significantly different. Think a password you have to transcribe.
If you know your font will be used in a quite small size, you may want one that is optimized for being read at tiny sizes. If you're displaying something technical, a monowidth font is better suited.
And all of this focused on utility for the most part; I'm leaving out all the reasons you'd want it for stylistic reasons. If you're trying to make people feel at ease, you may want typeface where the end of the strokes are rounded, for example. Sometimes you want people to feel a certain way, in the same way you modulate your tone when talking.