Relational dbs are based on relational model. It’s a giant black box of magic. And it’s magic is based on a bunch of constraints to make the relational algebra work. It’s really quite flawed for modern web apps.
You're gonna need to give me some more on why it's "quite flawed for modern web apps". I may even agree with you, but it's tough to know from what you've written so far.
Referring mostly to the query planner - you have no control over it, and you have to dive deep to figure out why it's making certain plans, and how it collects statistics to make these calls. Plus the planner essentially gives up at 6+ joins.
> quite flawed for modern web apps
Try listening to updates on a query.