Regarding tab colors, I’ll post screenshot from my Debian machine later tomorrow.
If something is better (or at least perceived as better) people will use it on their own. Default or not.
Examples: VLC player. Microsoft Office
Even if LibreOffice is free, why people are paying for Microsoft Office?
I have to spend 10 times more time on LibreOffice on Debian/Ubuntu than on Microsoft Office on Windows. Same with simple touch ups in GIMP vs Microsoft Paint.