Calling 4-5% marketshare microscopic is not fair. I get it if it was still stuck at 1%, but it's growing, and the rate of growth has been increasing too.
A growth of 4% over 20 years is not an increasing rate. And yes, 4% marketshare is microscopic. macOS has a bigger share but you wouldn't say macOS is massive. Posts like this are cheerleading OS's because everything needs to be a zero sum competition.
Is the desktop/laptop linux market share really over 4%? What is that based on?