Precisely. Tests take a substantial amount of time. Door staff could be tasked to check the results of self-administered tests, but monitoring their execution

Precisely. Tests take a substantial amount of time. Door staff could be tasked to check the results of self-administered tests, but monitoring their execution would be far too demanding. Expecting them to be able to administer them in a controlled way is unimaginable. Anything self-administered is open to gaming by the customer. Anything administered by venue staff is open to gaming by the venue itself — whether it is protecting scarce revenues, or just treating valued customers differently.