All 3 billion Android devices in the world. It's pretty crazy when you think about it. Also 96% of the top 1 million web servers and all of the 500 fastest super computers (excluding quantum) in the world.
Think of them like graphics cards. They are more of a component to do calculations that the cpu either can’t do, or would take too long to do. So calling something (the whole shebang) a quantum computer is like calling a computer training AI an ML Server.
Eventually, if things keep progressing, they'll be able to do certain things like factoring primes faster than conventional computers. But, the clock rate will probably always be abysmal.