what is the best use case for Clear Linux? In the end the kernel is common among all of them, so I guess you can end up adapting any version of Linux to what you want. Maybe he is a power user and he placed it ther because of that? The guy is mostly focused on gaming.
Clear Linux can work if you have a single or a limited number of server tasks that you want to run fast. All of its binaries are compiled with the most aggressive optimizations and it does indeed tend to benchmark a bit faster than many other Linux distributions, at least on selected benchmarks.
The problem is that once you have those tasks up and running, you then want to avoid doing any maintenance on that server in any way, shape or form. And the reason why you want to avoid that is the super inflexible way in which Clear Linux handles software updates.
Most distributions use some form of package management system to handle updates. These systems tend to maintain a map of dependencies, which keep track of the fact that a certain package X requires at least library version Y, which is found in package Z of a certain version or higher. And so you're generally free to add, remove, update and replace individual packages if, say, some crucial new functionality or bug or security fix is required.
That's not really the case with Clear Linux. It uses a system it calls 'bundles', which throw a whole bunch of software together, all of which is updated at the same time. That means that any update that you really want to install tends to trigger an avalanche of changes in a heap of installed software, completely disregarding whether any of it has some sort of major new release, possibly with big changes in functionality or even features gone missing. Major breakages are a regular feature on Clear Linux. You simply can not rely on automatic updates to not totally hose your system. So most administrators either do not update at all, or perform updates manually, offline, which is just bad.
And if you happen to fall behind just a bit on updates, it can take a very, very long time to run an update cycle, as it goes through every single release cycle that happened since your last update. And then on top of that the update process requires an absurd amount of disk space, so you can easily run out. At which point you still won't have a package manager to help you selectively clean up space.
It's not a distribution for gaming. It's downright unpleasant for desktop use in general. It's like an experimental wholly different approach to a Linux distribution, for.. reasons. They could've taken any of the infinitely superior existing package management solutions and just cooked aggressively optimized packages for those, but instead they chose to reinvent the wheel, and somehow ended up with a sled, stuck in mud.
