id Software, a much smaller company, open sourced the source code of almost all their games and ported them to operating systems known not to be profitable. The benefits of those altruistic decisions are simply unmeasurable. They did all this while still having to work an insane amount of hours to ship their ambitious products.

For example, not long ago, Quake II RTX was released by NVIDIA as a way to demonstrate the advanced raytracing capabilities of their new RTX cards. A decision made in 2001 (open sourcing Quake II) continues to benefit the world today.

Decades ago, Sun Microsystems open sourced OpenOffice, Java and Solaris. LibreOffice is a fork of OpenOffice and is one of the few office suites available free of cost.

Before Microsoft acquired Github, Github open sourced Atom, an editor similar in scope to VS Code. They also open sourced Electron, which is the framework used by VS Code.

Smaller companies have been doing much more. Microsoft has open sourced some interesting projects, but to say that companies are open sourcing projects because Microsoft is a pioneer in open source is just 4/20 talk.

Microsoft will never open source strategic projects like DirectX, Microsoft Office, SQL server or Windows. They will keep making money hand over fist.