Theoretical properties of quantum computers are all asymptotic. Asymptotic runtimes don't always correspond to real world performance. The hope is that we will

Theoretical properties of quantum computers are all asymptotic. Asymptotic runtimes don't always correspond to real world performance. The hope is that we will eventually be able to build quantum computers such that the constant factors don't mask asymptotic speedups for problem sizes that we actually want to solve. To figure out how to do that we build research machines.