I'm a big fan of JSON data in SQL databases. Best example is raw responses from payment gateways. You don't necessarily care or want to normalize that detail. There's no point in creating several tables per provider when you can store it in the payment record with success/fail.

There are many more examples. You can lean into it with PostgreSQL given the support for indexes against the nested structures.

Also with mentioning is PostgreSQL is supported by every major cloud provider, and you have growth options for scale like cockroach and others to grow into.