Also, this is an old quote. Databases didn't all support things like JSON at the time, so joins and subqueries presented an N+1 problem and could balloon data fetch requirements fairly easily. Being a GraphQL-focused ORM originally too, this made some sense.
The default is now being changed and correlated subqueries, JOINs, & JSON aggregation will replace the old approach unless explicitly toggled.
In my first job fresh out of uni, I worked with a "senior" backend developer who believed this. He advocated for crusty, bug-ridden ORMs like Sequelize and Prisma (still very early stage back then, so lots more issues than now though I'd still steer well clear of it). Claiming they did "query optimizations". I knew it made zero sense, but also that I wasn't going to be able to convince him.
Wow, what the fuck.
"Also, this chapter about Query Performance Optimization from the High Performance MySQL book has some great insights. One of the techniques it mentions is JOIN decomposition:
This belief that they can write JavaScript that outperforms decades of bare-metal executed optimisations in mainstream database engines is just astonishing.