Many businesses in the US check ID at the door. If you are underage, they don't let you in.

On the surface it seems reasonable to ask for an equivalent ID check online.

But. The bouncer doesn't photocopy my ID and store it in a poorly secured back room that is regularly raided by criminal enterprises or outright sold by unscrupulous owners of the establishment. Similarly, they don't check in with the government in a manner that leaves a record.

I'm fine with an ID check, but I think it is also reasonable to demand the same level of privacy that one gets when visiting a bar, casino, burlesque club, or similar establishment.