Just to cross the t’s and dot the i’s, I’d add that most system fonts will not work at all in the browser. This is because many ad services used the list of installed fonts as a way to identify a particular browser on the web, and profile it (related to so called “super cookies”).
So at some point 5 years ago we removed fonts that browsers won’t recognize from the list, as documented in this post:
The other aspect of random fonts installed in your system, is that most of the time the visiting browser will not have that font, so that font will be replaced with something else. While in some cases they will be replaced by something reasonably similar (say a plain serif or san serif font), often times it will not.
So in most cases what’s best is to install the font as a custom web font, and use it as a web font.