And because Windows and it’s eco system of applications he listed gets worse, he extrapolates this to all software.

They admit that bias in the article:

[...] since I've always been working in the Microsoft tech stack, I use a lot of it. Thus, selection bias clearly is at work here.

Now, I mentioned free software as the exception. I don't have any data as to how big free software vs proprietary software. But I think his points extends at least to other proprietary software and is not limited to Windows.

Some software get better, some get worse.

I can agree with that.