What difference does it make what font a website uses? I get having a monotype, a serif and possibly a sans-serif, obviously setting the font size should be a thing, but the actual font?
I just don't see what difference it makes if a website is in Helvetica, Times New Roman or Arial. If one font is easier for me to read than another I can chance it in my browser, which makes more sense than letting some web designer, who's more focused on brand identity, pick a font for me.
There might be some cases where you really wish you could pick a specific font, but you can't really use it to convey meaning anyway, because that would not work for screen readers or people who chance the font on their system to help readability.
Why would a website need a different font from the system font? I can get that there's "better" fonts (or at least worse ones) with different kerning or whatever, but surely people want a good font for everything? So the system is the right place to fix it.
Firefox lets you disable the ability for web pages to override the system font, and I did that a while back. Throw web fonts in the bad idea pile with blink and marquee.
Yes? A massive amount of material on the web (including basically everything worthwhile) is given and frequently even made for free. In any case, that has nothing to do with the user agent. Why would browsers (the agent of the user) implement functionality to make more effective advertisements?
For the same reason that an OS like Windows puts ads in their Start Menu, presumably.
Because their audiences are either captive, uneducated, uncaring or a mix of those and therefore will accept whatever defaults you throw at them. If those defaults help you as the org to make more money, then it’s a no brainer.