You're coming off as pretty ignorant here.

Most diseases aren't [very] contagious until a person is symptomatic. That was the case with e.g. SARS, and why it fizzled out after a while. Symptomatic people isolated = no more SARS.

Covid is relatively unique in that it's contagious 2-3 days before a person even knows they're sick, basically reaching peak viral load right when a person starts developing symptoms.

So... testing asymptomatic people for Covid? Yeah. Duh. That's not ridiculous, it's common sense, for anybody who has the faintest idea how Covid is transmitted.