Comment by Fnoord

A website could offer accessibility features, such as dark mode or dyslexia font. These could be subtle, or very obvious, depending on your target group. Large amounts of texts (e.g. a testimonial) could be a valid example. If you go for site-wide, you got consistency. If you'd apply it on h1-3 you'd put emphasis on the titles.

It'd be great if say Mozilla Firefox included this font natively (for the app itself). Then again, the default is currently Times New Roman...