One typeface shows up more than any other in the library. What the runners-up reveal is more interesting.
When I tallied the body fonts across the library, one name sat clearly on top: Inter. It is not close. But if you stop reading there, you learn the wrong lesson. The interesting story is in the runners-up and in a pattern that has nothing to do with which font you pick.
Inter is excellent, free, and endlessly legible at every size — a genuinely great typeface. It is also the safe default for a generation of products and, increasingly, the automatic output of AI tools. So its dominance is two things at once: a lot of good taste, and a lot of not choosing. The typeface is not the problem; defaulting to it without a reason is how pages start to blur together.
Behind Inter, the tail is telling: Suisse Int'l, Geist, Neue Montreal, Matter, and a scattering of serifs and monospaces. These are the choices of brands that wanted a specific voice — a little more warmth, a little more edge, a little more character than the default provides. The runners-up are where identity lives.
Here is the finding that outranks any font name. Most of the best-typeset sites do not "pair" fonts at all — they run one family and get their contrast from size and weight. A single grotesque, a huge light headline, a quiet body, maybe a monospace for labels. One family keeps a page fast and coherent; the scale does the design work. When they do pair, it is usually one expressive display face over one quiet workhorse — not three competing voices.
Inter is a fine choice. Just make it a choice. If you use it, own the scale and the tracking so the page still has a voice. If you want character, the free alternatives to the expensive faces are genuinely good — I listed the mapping in what top sites actually use. And whatever you pick, resist the third font. Two families, maybe a mono accent, is where coherence lives.