That is a solution applicable for a document or GUI created by yourself, where you can define various styles with associated fonts and use them appropriately.

However, I see the worst offenders on various Web pages (frequently for various URLs) where I do not control the typeface, unless I instruct the browser to ignore the style sheet of the rendered Web page and use my own fonts instead, which can be tedious or create other problems in the rendered page.

I have a few CSS overrides for some websites to turn all input boxes into monospace fonts. It is far easier to use them then.