The term that I prefer to use is, “cooperative development.”
Computer software is anything but “free.” In fact, it’s one of the most expensive things on Earth. Many a company that is built on the proprietary model has gone onto the rocks of revenue, and has taken their otherwise-good product with them.
“Cooperative development” is predicated on the notion that a rising tide lifts all boats. Companies and individuals agree to cooperate, in an organized way, on the mutual development of a software product. They do so because, by law, the terms of their cooperation are protected. Everyone shares what they develop and is guaranteed access to what others have shared. No one can put a fence around the thing and start charging admission. Copyright licenses such as GPL have been tested and upheld in courts around the world. They have teeth. So, companies can participate, and the interests of their shareholders are still protected.
The process has been shown, many times over, to enable advancement of software development far beyond what could be achieved under the proprietary development model. It has been very successfully used to establish the foundations upon which other proprietary offerings can be staged and deployed. For instance, the proprietary OS/X (macOS) and iOS systems are built on top of (open source) Unix Darwin. And, nearly everything is compiled with the open-source gcc compiler suite.
You simply wouldn’t have much of the critical software upon which the Internet is built … without cooperative development models. No one could afford to do it (alone). Remember that Blender itself was basically rescued from a bankrupt company, and money changed-hands with the then-creditors to secure the intellectual property rights. “What happened next” is because of cooperative development being able to achieve what the proprietary model could not.