Random number from a Reddit thread isn't a great source but even then I agree with some of the comments, it might even be 99% nowadays.

The question is what does it change? Are the contributions from those corporations irreversible or are they targeting their own products for e.g. virtualization for cloud computing which doesn't affect the typical personal OS user?

Anyway the kernel itself was still started by a random student in his dorm. GNU was just started by another student. That possibility still exists today. It's also possible to trim that kernel with e.g. Linux-libre or even run Hurd.

One can use Debian with KDE today and see nor be subject to any corporate impact in terms of arbitrary limits to their usage. If they decide to not personalize it more it is most likely because they didn't consider it, not because they can't.

It would be bad if there weren't a significant number of companies paying for work on Linux to continue, because so many of them are benefiting from it, and at least some of them realize that ensuring sustainability into the future is a good idea and worth investing a salary or two. (As in, paying some of their employees to work on Linux).

Don't fall into the trap of assuming "A big company did it / paid for it to be done, therefore it must be bad". I see that mindset (which I'll call anti-corporatist) on HN from time to time. Companies are made up of people, and it's the people that make the decisions. Some people are good-natured, some are greedy and grasping. And the company that acted one way one decade can turn around and act completely differently the next decade, because a different person was at the helm.

Fundamentally, it's about the people, not the companies. The anti-corporatist mindset is prone to forgetting that.

That's the beauty of containers, virtual machines like QEMU or compatibility layers like Wine/Proton. As long as your super esoteric software implements the interfaces those rely on, you are able to run everything else.