Umm...font loading is blocking. Not in a bytes transferred way, but in terms of user experience. Text disappearing for a font to load is not a good experience.
Unless the website is an art piece, portfolio, or something similar, where the typographic design actually matters, I'd say the system fonts are a better choice.
Umm...like I pointed out, it doesn't have to be as we now have "font-display" which provides multiple strategies for loading (or not loading) web fonts.
Unless the website is an art piece, portfolio, or something similar, where the typographic design actually matters, I'd say the system fonts are a better choice.