Why a custom font?

[thany]

Using a custom font, cross-device, cross-browser, cross-language, and cross-settings, is VERY HARD. It's a real chore to get a font to behave absolutely perfect across all these things.

Related issue:
https://github.com/vector-im/element-web/issues/15594

The font appears to lack hinting, which is absolutely neccesary for crisp rendering on regular-DPI screens. If a font reduces legibility, its usefulness is objectively reduced.

As an end-user I couldn't care less about a custom font, especially given the fact that your Inter font looks absolutely run-of-the-mill, like any other sans-serif font. Without it, using a system sans-serif font, the whole app looks fine. It really does. So why am I being presented a custom font that not only looks completely identical (to me) to a system font, but also reduces legibility on LDPI screens? This font only creates disadvantages, and no advantages, as far as I can tell.

The question is: why is this particular custom font so important?