Comment Re:Kernel support (Score 4, Informative) 24
A kernel.org release or stable release is not considered to be a "one size fits all" solution. For example, there is a kernel defconfig file that distributions will adapt to best match the requirements of their users.Such as running on ARM64 instead of x86-64. Additionally, distributions may provide extra kernel drivers that are not in the kernel.org tree such as drivers specific to chipsets that are not supported in kernel.org.
You are correct in saying that application software running in userland is mostly independent of the kernel version but application software is dependent on libraries that interact with the kernel. Therefore, there is some wiggle room to have a mix and match approach between kernel, library and application versions before breakage occurs.
Also, end users can build their own custom kernel and deploy it. This is particularly necessary when resolving kernel bugs in the community and for sending proposed fixes to the kernel.org mailing lists.
If a distribution adapts the kernel then these adaptions need to be incorporated on top of the next LTS. This prevents an immediate switch over to a new LTS kernel.
It should also be noted that a LTS kernel release may have deleted an API or removed a feature that the distribution was using. This can also delay upgrading to a new LTS kernel release as time is needed to find a solution.