Valve contributes effort to Wine via Proton, and provides open source software like Steam Audio.
EA does something similar, and their EASTL is an opinionated and gaming-focused container and algorithms library that they maintain and made open source.
Many corporations are free-riding on the Open Source they use. As most of us are honestly.
But I think people cynically underestimate the value of the contributions corporations do make and fail to understand just how much of the software we enjoy is only possible due to corporate funding.
Igalia may be a good example as most of have are not even familiar with them. But the Linux distro that I use comes from their, the Servo browser is being driven by them, and many other projects benefit from their contributions.
EA does something similar, and their EASTL is an opinionated and gaming-focused container and algorithms library that they maintain and made open source.