Is there a QC out there that can perform a commercially useful computation? No, not yet. And yes snake oil is abound. But the reality is not two categories, it's a spectrum. Some are more useless than others.
It's like fusion energy: there are legitimate companies working on the problem, and they may even succeed at some point, but anyone willing to deliver a 1MW fusion plant tomorrow is scamming you, because the technology doesn't work yet.