That hasn't been the case for most of the decade. I already told you what does: Completely custom-built hardware that can do nothing but bitcoin mining, such as Antminers.
alright, in that case you're right, the processors seem wasteful
though interestingly, the specialized processors alkso seem like an example of a second order effect of bitcoin: driving innovation towards more energy efficiency. (though the tradeoff here seems to be wasting materials versus wasting energy)