Has a quantum computer been built that can solve a problem faster or cheaper than conventional hardware? Afaict no. From an outsiders pov quantum computing seem

Has a quantum computer been built that can solve a problem faster or cheaper than conventional hardware? Afaict no. From an outsiders pov quantum computing seems to be advancing, but until the science and engineering can overcome the challenges and build something that can do something useful, then it seems too early to study it (outside of curiosity, the theory is kind of interesting).