This is the company that put glass on the back of their phones for aesthetics we're talking about here. Nothing is out of the question.
The most common ceramics are strong but brittle and lightweight. I wouldn't assume that these would make good choices (for example, weight alone is a reason to choose aluminum over plastic...it weighs more and thus feels more expensive). But there are still some interesting alternatives out there that would be cool to consider. Like possibly monolithic and completely waterproof circuits with near perfect insulation that can be cast instead of printed/assembled. Or possibly structural batteries? Who knows?
They're also a huge variety of materials, it's like asking why plastic is a good material - do you mean silicone rubber, ABS, or Teflon?
Tell that to samsung, joking aside a ceramic case might be useful if a battery cooks off.
But very rarely are they not brittle upon impact.
This is why you don't see ceramic saw blades - carbide, even though brittle, is much less brittle than ceramics.
(this is also why they don't use diamond saw blades except for abrasive cutting - the diamonds we make are too brittle to be used to cut wood).
To clarify, "carbide" here is short for "cemented carbide", i.e. ceramic carbide particles sintered together in a metal binder. It's tougher than the pure ceramic although still somewhat brittle.
But ceramic still wouldn't work.
(at least what we are talking about here. In theory, cemented carbide can be a ceramic, depending on the exact terminology used).