To create a usable Linux system you need a Linux distribution, which assembles the kernel along with other various "part kits" into something that can actually run and do useful work. The problem is there are literally hundreds of such distributions around, and several dozen that are considered "major" distributions (see Distrowatch for details).
How to choose one vs another? How are they supported? The answer is all over the map and this fragmentation is the primary reason why Linux never gained any real traction as a mainstream desktop OS. That's not a critique as it was originally a hobbyist system that "got away from itself" and went mainstream.
Even once you settle on a distribution you still have to customize it and find and install applications on it, which again tend to be quirky and with a few notable exceptions (e.g., web browsers) are at best irregularly supported.
Linux is the standard server OS because it is free and nearly infinitely customizable, which suits the needs of data centers who have a dedicated IT staff. For the home user, unless you yourself are a hobbyist it's simply not worth the bother as most people just want to use their computer and not tinker with it.
I'm not aware of any IT pro who would recommend their non-technical relatives try running Linux at home. I don't expect that to change.
Interesting point. I used to be a UNIX admin back in the day and always thought of the kernel as being the OS. For a while all we had was the command line interface. Then we got Motif and Xwindows. I never considered that as part of the OS. I always just thought of that as a GUI to the OS.
Windows seems to have clouded all this. By calling their Windows system as OS they expanded the definition of OS. Now it was no longer just about supporting the basic operations and maintenance of the computer. Now the OS included all of the interfaces to the peripherals and to the user. I believe they even put File Explorer at the core of their OS even though that's really just a GUI file picking tool. Then they were even going to put Internet Explorer at the core of their OS. Thank heavens they were prevented from doing that or the hackers would be ruling the world as we speak.
You say kernel, I say OS. You say OS, I say OS plus GUI.
Maybe it would have worked out better for everyone if each computer came pre-installed with and optimized OS (you say kernel) and customers chose their own preferred GUI.
Oh wait GUI was UI and is now UE.
I can't keep up.