[m-watson]

There is hardware, it isn't imaginary. It just isn't very robust or extensive yet.

[AlexCoventry]

There is hardware which purportedly does a quantum computation, but it's completely useless even as a proof of concept, unless you have a burning need to randomly sample from the distribution it happens to generate.

[FartyMcFarter]

> but it's completely useless even as a proof of concept

We might have different definitions of "proof of concept", but I think that's exactly what it was (if you're referring to Google's experiment).

This FAQ explains this quite nicely:

https://scottaaronson.blog/?p=4317

[R0b0t1]

An interesting idea is simulating quantum math on real hardware. It's an open question if quantum computing is equivalent to contemporary computing. It seems likely that it is.