It used to be that one of the big selling points of Mozilla/Firefox was that it could run on almost any OS!
What happened to all of that?
Not having to ensure compatibility with really old operating systems enables the developers to spend more time adding features and capabilities, for one.
"Today's robots are very primitive, capable of understanding only a few simple instructions such as 'go left', 'go right', and 'build car'." --John Sladek