That's the thing, not everyone is a professional photographer. Open source tools are fine for many of us. They are also great to get a taste of a field, to learn the basics, without a massive investment.

You don't have to be everything to everyone. You just have to satisfy a need.

I'm not a professional photographer though. I'm also not a professional musician, either.

Yet, Darktable allows me to process my RAWs to a point which I like. Similarly, my audio equipment allows me to create some music which I like, too.

I didn't push Darktable to professional levels, but I believe it can match bigger tools for what I want to do with it. I don't do photo manipulation, for example. Just process RAWs. I expect the same from my audio equipment for my music endeavors.