It definitely could happen, but there are two things standing in the way of it:
- there's not one desktop Linux that everyone uses (or even uses by default), and it's not resolving any time soon
- I use Ubuntu+Gnome by default, and I wouldn't say it looks great at all, other than the nice Ubuntu desktop background, and the large pretty sidebar icons
- open source needs UX people to make their stuff look professional. I'm looking at you, LibreOffice
Forget looks - I'd just be happy with rock solid.
The standard Ubuntu+Gnome desktop crashes far too often.
Now I have no idea whose fault that is ( graphics driver, window system, or desktop code - or all three ) - but it's been a persistent problem for linux 'desktops' over many many years.
Imho the bright side is that this has solutions and it is getting better. Linux can be very stable, look at servers to android or even steam deck. It's mostly hardware lottery that means it comes down to hw companies support.
The kernel is stable, the desktop ( in my experience ) is not.
I suspect a lot of the problem is in the graphics drivers - they just don't get the love and attention that happens for Windows, and definitely not the Mac ( where they intentionally keep the number of things they need to support low ).