Commercial open-source software is open-source software that is being developed for commercial exploitation. Often, there is a single vendor behind the software (Elastic, Mongo, etc.) which tightly controls the intellectual property and the software’s roadmap (in contrast to community open source that typically has a wide range of stakeholders and broadly distributed copyright). Sadly, the fate of commercial open source appears to be that it starts open and ends up closed. More specifically, vendors license away from an open source license to source-available or other license. Now then, should you use commercial open source in your projects and products or not?
I recommend you view a dependency on commercial open source as a short-term gain (you get quality software, for free) and a long-term liability (payment day will come).
With payment day I refer to the vendor tightening the screws to turn open source users into paying customers. There are many ways of how this could happen (delayed releases of the open source code, features missing i.e. open core model, or simply no open source license any longer). You should be ready for this situation by budgeting for either paying the license fees or migrating away to alternative solutions. Don’t forget about this! With commercial open-source software, one thing is sure: Payment day will come.
A longer explanation can be found on my professional blog.