Becuase it's still integral to countless businesses operations.

Because any time anything changes in Windows, people bitch about it.

I dare say, that 90% of all companies in Europe and US, use Windows. And lots of companies relies heavily on software built 20-30 years ago. Microsoft knows this.

That's why they are very reluctant to "touch that piece of code from a quarter century ago" because there's probably a lot of software that would break without it. Software their target audience need.

You ever worked in like a real job? Have you ever seen the amount of legacy code that depends on some other legacy piece of shit which itself depends on...?
It's absolutely maddening, being there, diagnosing the issue and absolutely having no way to do anything about it because no time, not allowed, no need if it ain't broken, our customers rely on this specific version, etc.

It's not a Windows way of thinking, it's what every single one of the businesses I've worked with for the last twenty or so years think like. And changing shit is incredibly expensive.