Lazarus should be more, but Firebird not.
Reason: in case of database back-ends stick to mainstream.
( and Firebird is certainly not the most stable...)
As Thaddy says, my inclination is to stick to the mainstream: SQLite for local stuff, PostgreSQL for anything which might possibly need multiuser or remote access.
Here we go again.
I believe that most of us here prefer to use Lazarus / Free Pascal for a number of reasons, but will any flavor of Pascal - including Delphi and Lazarus / Free Pascal - represent the mainstream in the world of IDEs or programming languages as you are suggesting as a criterion for choosing a database?
If you really think so, I will wait for your consistency in stopping to indicate Lazarus and Free Pascal to the newcomers who arrive here and start indicating for them to use an IDE and a programming language that is
mainstream because obviously Pascal is not. It was, but it hasn't been for decades.
As a data professional for over three decades, I can say that if you are unable to get good results with Firebird (or any other DBMS), stop bading-mouth what you obviously don't know and start hiring professionals who study and deliver performance and qualitiy.
I would say the same to people who bads-mouth Pascal just because they don't study it and don't know how to use it. This is as stupid as bading-mouth Firebird without studying it and not knowing how to use it through time and specially current.
Let those who study and use Firebird current and routinely speak good or bad things about it, just as we should give preference to hearing good or bad things about Pascal from those who study and work with that programming language.