These days, feature-wise, it's probably somewhere in the middle. It had support for things like window functions long before they became available in MySQL and friends.

What it gives you over both is single-file databases which are easy to share, and in-process embedded mode, just like SQLite.

Unlike SQLite, it doesn't only support embedded mode, but can also be turned into a "server" DBMS that supports remote access from multiple clients (like MySQL/PostgreSQL). Hundreds of concurrent connections work fine from what I've seen. This can be changed in either direction at your discretion, the database file remains the same.

My favorite anecdote relating to Firebird/Interbase (its original name) is that it is supposed to be renowned for its durability (i.e. resistance to corruption) and fast start times.

Because of this, they used it within the internal systems of the M-1 Abrahms tank.

Apparently when the main gun is fired, it gives off such a powerful energy impulse, that there is (at least was) a tendency for it to crash the internal systems.

So, they adopted Interbase because of its ability to work well in an environment where hard computer crashes are more a norm than an outlier.

> Postegres is all the rage, MySql is the og

From "influencers" i.e. YouTubers?

OG real world was Oracle and SQL Server.