Prisma is definitely limited when it comes to advanced use cases. I have been using it for two years and we are now moving to postgraphile because of this. And Prisma 2 doesn’t help, it makes it worse.
Yes, Prisma allows you to run hand crafted SQL queries. That’s is the bare minimum I would expect from it. Graphile on the other hand allows you to do this AND to systematically generate whole classes of such requests, through plugins.