BTW, Matias' keyboards cases are made of polycarbonate like Apple's keyboards before they went with aluminium. Old IBM Model Ms had cases of PVC.
Most keyboards with mechanical switches have switches mounted in a metal plate made from sheet aluminium - inside a plastic case. Corsairs keyboards are not more metal than the norm: they merely have the sheet-metal plate
exposed. The bottom and sides of the Corsair K70 are still regular ABS plastic.
Then there are keyboards where the case is made of solid aluminium. For instance the entire top of the Cherry MX-Board 6.0 - it has a bottom of plastic but still a whole lot more metal than any Corsair keyboard.
Look also at the
Input.club K-type on Kickstarter, which also has "floating keys" like Corsairs but where the case is made from solid aluminium and not just from sheet metal - all of it except for the side-glow lighting strip.
And then there have been many different high-end enthusiast keyboards made from solid aluminium, as well as aftermarket aluminium cases for a couple of popular keyboard models. All solid, all aluminium.
But enthusiast-grade stuff is not what "typo" is asking for.