"Results showed a small, but significant advantage in response times for words written in a sans serif font."
https://www.tandfonline.com/doi/full/10.1080/20445911.2011.5...
"Sans serif, monospaced and roman font styles significantly improved the reading performance over serif, proportional and italic fonts."
https://dl.acm.org/doi/abs/10.1145/2513383.2513447
and here a whole book about that question