Google and Microsoft are some of the biggest contributors to free software in the world. Free software is mostly a way for huge companies to cooperate on IP, at this moment, or roughly equivalent to shareware for smaller companies who want to give you a taste of the software before you have to commit to buying.

There are definitely many exceptions, such as Mozilla and GNU and others, but some of the highest profile software fall in either the first category (Linux, Clang, Kubernetes, Docker, MySQL, OpenJDK, PostgreSQL) or the second (old AGPL MongoDB, ElasticSearch, CentOS).