Android runs an only slightly modified Linux kernel, and yet the OS requires much less from the user than e.g. Windows or MacOS.
Chromebooks run a bog-standard Linux kernel and the target audience is kids.
My car’s entertainment system runs a standard Linux kernel, and the UX is so cut down that PC expertise really doesn’t matter when using it.
MacOS and iOS, two systems known for their ease of use, both stem from BSD, which comes from Unix.
The kernel has nothing to do with this.
In fact, the only mainstream kernel used in user-facing operating systems that doesn’t “come from Unix” is Windows. Everything else is derived either from Linux or BSD, which both are derived from Unix.
There isn’t even a mainstream phone OS anymore that doesn’t “come from Unix”.
If you don’t root your Android you can even run a full desktop Linux in a proot container. You can run all Android apps and Linux apps on it. Using Winlator you can even run most Windows apps and there are emulators for most systems out there. If you cann that “barely anything” you are lacking imagination.
Apparently you haven’t used Chromebooks or MacOS, but you clearly misunderstand the topic at hand.
There’s always a balance between configurability and stability, and every single OS, even Windows, falls somewhere on that spectrum. If you allow a user to break their system, the downside is that they can break their system.
iOS, unrooted Android and ChromeOS fall on the “less ability to break your system”-side with Windows and MacOS following rather closely, and different Linux distros are on the full spectrum in between. Immutable distros make it harder to break yous system at the cost of immediate configurability, while running Arch you can do whatever you want and you’ll likely destroy your OS while doing so, if you don’t know what you are doing.
Again, all of that are choices done in user-space, nothing about that comes down to the kernel. You can make any Linux distro entirely unbreakable by taking away sudo rights for the current user and making every non-temporary directories and files read-only. You can do that in 10 minutes and suddenly there’s nothing the user can do to break the system. But the user also loses a lot of abilities. Again: all of that is user-space only and has nothing to do with the kernel.
And yes, there are enough stable and comprehendible Linux distros out there, but if the user has sudo rights and the constant and uncontrollable urge to destroy their system, they will find a way to do so.