The most complete review of cryptocurrency mining hardware, GPUs, CPUs, and custom ASICs, collected by the Sia file sharing team. They built their own hardware in order to fully understand it.
Their summary is that because manufacturing hardware has economies of scale, it will tend to be centralized. Also, since cryptocurrency mining hardware is essentially a “money printing machine”, that manufacturers only sell crypto mining hardware when they can make more money selling it to customers rather than just running it themselves.
All of this applies to anything that runs a Proof of Work (PoW) algorithm. The dynamics of networks that use Proof of Stake (PoS) or other types of consensus will be different.