There are specific cases where a non SQL database is better. Chances are if you haven't hit problems you can't solve with an SQL database you should be using an SQL database. Postgres is amazing and free why would you use anything else.
People keep saying there are specific cases where NoSQL is better, but never what any of those cases are.
Time series is one. Consider an application with 1000 time series, 1 hosts, and 1000 RPS. You are trivially looking at 1M writes per second per host. This usually requires something more than "[just] using a RDBMS".
a bit more context: High-velocity transactional systems (e.g any e-commerce store with millions of users all trying to shop at the same time), I helped to build such a 10 years ago here is the presentation - https://qconlondon.com/london-2010/qconlondon.com/dl/qcon-lo...