Linux is on more computers both today and all of the computers ever made put together than any other OS. It is on virtually all servers on the Internet, the majority OS on phones, its in many TVs and STBs and streaming sticks, its one of the few OSes ever in space, its one of the few OSes ever on Mars, and it is also the OS behind ChromeOS (which that article mistakenly breaks out as its own numbers; so by their own admission, its at least 7%).
The largest desktop OS on that list? Windows.... made by a company who makes more money off Linux than anything else, is the largest corp contributor to Linux, and has far more Linux machines internally than Windows ones, and hires software developers who do not develop for Windows.