Every Magento 2 store needs fonts to display styled text. Like other static assets it use bandwidth. It affects performance, if do not download before text required it. I am adding few suggestions for font optimization and some resources links as well. I will keep updated information for font here
- Try to use google font (why? read this link)
- Use no more than two fonts and check their size as well.
- Load them on priority basis using preload and swap to avoid invisible text during font loading (check this link)
- Use proper caching for fonts (check this link)
- Use less variants of fonts
You can check complete speed optimization guide Magento 2 speed optimization