One of the comments there made the excellent point that the lib was still 'early access' which most mature devs wouldn't use for production. Maybe if it was 1.0.0 prod-ready, use would have skyrocketed but Prisma would never know that.
Looking at other popular JS projects, they monetise by basically creating a ‘cloud’ offering which is just re-selling AWS resources in a highly specialised way.
https://github.com/prisma/prisma-client-go/issues/707