Linux works fine on older machines and can give them new life.
I recently had to use a smart phone that is over 10 years old (Samsung Galaxy S5 mini) and believe it or not, YouTube and Facebook Messenger still worked. It was slow a hell but it still worked fine.
Staying on an old and unsecure OS sure is a solution, but it’s incredibly fucking stupid.
At least you could install Linux and use an old Windows version inside a VM instead of running a vulnerable system on bare metal. That way you can still use Windows when you need to.