[PeterisP]

Part of the reason is not bureaucratic but that clinical testing simply takes enormous amounts of labor, since you need to do it at a large scale.

Alternatively, you could say that the requirement to do that much clinical testing is an arbitrary bureaucratic decision and could be lowered - but there are political reasons (e.g. thalidomide) to err on the side of caution even if extra testing saves less lives than it costs lives because of the delays.