They can, but they won’t. Microsoft is run by the most cutthroat sycophants you could possibly imagine. That money you mentioned is going to those aforementioned sycophants and shareholders.

But will the earn more money by offering a better weather app?

You should view it as an invitation to write a better app, like that guy that wrote a windows terminal to replace the garbage Microsoft wrote.

I wish... If only explorer.exe was opensource. If only the whole userland was opensource. We can only dream.

Seems very wasteful to help MS make their closed system better.