I think the better way to look at is that no matter how good Linux gets, if MS didn't shoot themselves in the foot it would always struggle to make headway. Even the modest headway it's made over the last couple years.
It's not about quality, it's about market dominance. Walk into any major retailer, 95% of the computers they sell have Windows on them (100% if they don't sell Apple). Go to any company and see what they run on almost all their computers, Windows. Go to any school, probably the same thing (though years ago Apple would have had a strong presence too).
And that's not even talking about business software like Office. MS built that dominance back when Linux was almost entirely focused on the server space. What Desktops did exist where mostly hobby projects or relatively small companies. Shit Linux itself was a hobby project lol.
MS has had that position for over 20 years. Windows is the Xerox of computers. A lot of people don't even realize there are options out there. In that environment, even if the Linux Desktops got better than Windows, it should have taken an absolute killer app or some big evolution in the space to get people switching. All MS had to do was keeping offering a competent product. Or even a kind of shitty one that didn't actively give people a reason to switch.
But they can't help themselves. Most of the money isn't enough, they need all the money. And they've degraded their product to the point where it is actively driving people away. And even now it'll probably take another decade for Linux Desktops to break the 10% mark.