At system level, the default fonts for wordpress are defined in theme.json file. You can speed up loading of site by just using these default fonts.
I have extracted this code from twenty twenty four theme code definitions.
Sans-Serif
{
"fontFamily": "-apple-system, BlinkMacSystemFont, avenir next, avenir, segoe ui, helvetica neue, helvetica, Cantarell, Ubuntu, roboto, noto, arial, sans-serif",
"name": "System Sans-serif",
"slug": "system-sans-serif"
}Serif
{
"fontFamily": "Iowan Old Style, Apple Garamond, Baskerville, Times New Roman, Droid Serif, Times, Source Serif Pro, serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol",
"name": "System Serif",
"slug": "system-Serif"
}