> case-insensitive

Tbf you can also achieve this in Postgres, it's just not present by default. From the docs [0]: CREATE COLLATION ignore_accent_case (provider = icu, deterministic = false, locale = 'und-u-ks-level1');

0: https://www.postgresql.org/docs/current/collation.html

If you run a single application, or a few instances of the same application, you don't need an external pool and most frameworks have an internal connection pool anyway.

Not sure if I'm missing anything here, but if I want case-insensitive search I simply create an index on lower(column) and use that to query.

VACUUM is something you need to pay attention to at scale. And at that point you need to know your DB anyway and tune it. For smaller applications (and I don't mean only toy applications) it usually isn't an issue.

> * No need for a connection pool, while many use cases with Postgres require PgBouncer and Co.

is there a strong evidence you even need client side connection pool at all? What is the purpose?

The limitation is that you have many clients with connection pools, they hold internal PG connection without allowing it to be reused by other clients..