small teams and individuals have failed to make enough money selling technical tooling products since forever; enthusiastic engineers keep building them. source: the 1990s

I think DB Browser is not a product but a feature. It is fairly challenging to monetize it. It can be an entry point for a developer's workflow, and then you can upsell something else.

For 12 years I got banks to pay for an editor I created. But yeah to grow the audience I made the database client free as others wouldn't pay. I have also created a separate BI tool so you're totally correct.