This is clearly the case today, pending some new discovery or intellectual leap surrounding consciousness. For all I know, you are unconscious, and your purpose was to type that comment so as to trigger my realization I am the only conscious being in existence :)

(Not a good way to live your live, but a theory consistent with the evidence.)

And that’s why solipsism is not entirely defeasible. You can’t be certain other people are conscious. But it’s reasonable to think they are. It gets harder with other animals, and even worse with machines. See Ned Block’s paper on The Harder Problem and Commander Data.