https://wccftech.com/macs-with-face-id-arriving-in-couple-of-years/

Apple introduced Face ID on iPhones in 2017 and slowly transitioned the security feature to the iPad Pro in 2018. Strange enough, even after several years, we have not seen anything similar on any Mac. Unfortunately, that might remain the case for a couple of years, according to the latest info.

A newsletter from Mark Gurman states that Apple is planning to shift all iPhone, iPad, and Mac models to Face ID, but the entire transition will take some time to complete. The company is also expected to bring Face ID to the cheaper iPhone models such as iPhone SE and iPad Air, both of which sport Touch ID, at least for now. As for why Apple has not introduced Face ID to Macs, it could be cost-related.