And how many times was all that code rewritten?

Sure, test it, but in a virtual machine first. Then read up what you actually want.

It is actually a competitor. Mean Microsoft have to improve if they want to keep the users. With the Windows 10 EOL soon they will give up on those users on those computers. Basically forcing anyone else to take care of them - Linux stands there welcoming them. Users just need a push or someone saying try this for free.