Open source is the best way to deliver software.

Closed source libraries are a pain to distribute. If you only provide binaries and not the source code you need to generate every single combination of platform and compiler, which specific versions, including all the external libraries it uses. It's simply crazy and a huge pain. One perfect example of this is CUDA from NVidia, it's a nightmare to use it because everything has to match exactly, including your OS version as the libraries needed usually come with the distribution.

With Open Source you can compile it anywhere. You also get to see what is does, and you can tweak it to fix bugs and improve it. None of that is available in closed sources.

You also can grow a community with open source, where other people fix the code and gives it back to you. Most software we have today is based on open source.

In terms of money, then it depends on your specific project. Open source has no limitations on making money. You just have to generate value with it so that people want to pay. A simple example would be selling the compiled version of your open source code, but there are multiple ways of doing it. You could have a "Community Version" open source and have extras paid, etc.