Yes it’s hard, but we do quantum computing research without any quantum computers. Lampson launched work on covert channel communication decades before the vulnerability was exploited in the wild. Turing learned a lot about computers before any existed. NASA does a ton of analysis before they launch something like a Mars rover, without the ability to test it in its final environment.
But will all the sparrows be so cautious?
Yes it’s hard, but we do quantum computing research without any quantum computers. Lampson launched work on covert channel communication decades before the vulnerability was exploited in the wild. Turing learned a lot about computers before any existed. NASA does a ton of analysis before they launch something like a Mars rover, without the ability to test it in its final environment.