Interestingly, Linux might be right behind it, at second place, dominating servers, cars, and all sorts of industrial devices.
But funnily enough in the end, when it comes to laptop and desktop computers, the Windows NT kernel, and the macOS Darwin kernel are still the reigning champions. It’s funny, because I think in the 90s, every OS designer was trying to take the place of MS-DOS/Windows/Mac. The two flamewar[*] buddies won out in the end, but likely not in the market segments they had initially expected to win.
There are 3+ Billion of Android Smartphone alone, and that is excluding the Tablet, SmartTV, Server, and other gadget making the number much closer to 4 Billion.
The fact that Android apps don't directly call the Linux API is not at all relevant (unless Google switch out the Linux kernel for an alternative like Fuchsia/Zircon). The discussion here is about OS market share.
I would argue that L4 is closer to "unix like" as a class than it is to Minix or Linux. The L4 kernels share a common API, but not necessarily a common ABI. Of course it's complicated because L4 itself is minimalistic, and the common API means you can get a monolith with a pluggable L4 kernel so there isn't a true apples to apples comparison.
My phone runs Linux. My GF's phone runs Linux. My TV runs Linux, too. So does the TV box-set (cable provider), and the zipitz2 runs Linux within OpenWRT.
Interestingly, Linux might be right behind it, at second place, dominating servers, cars, and all sorts of industrial devices.
But funnily enough in the end, when it comes to laptop and desktop computers, the Windows NT kernel, and the macOS Darwin kernel are still the reigning champions. It’s funny, because I think in the 90s, every OS designer was trying to take the place of MS-DOS/Windows/Mac. The two flamewar[*] buddies won out in the end, but likely not in the market segments they had initially expected to win.
[*] https://en.wikipedia.org/wiki/Tanenbaum–Torvalds_debate