its not a general purpose computer no, its a specialized tool for doing very specific things with limited use cases. you won't be gaming on your quantum pc anytime soon
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the main reason is that computing with physics is really difficult.
create a quantum algorithm is like trying to build a program that consists of throwing stones into a pond and trying to encode the answer in the constructively interfering waves.
that's why there are only like 5 discovered algorithms (limited use cases).
i honestly had no idea how shor came up with it. i mean if you just look at him he's a giga nerd.