The finances expended in the provision of aircraft resources for all Presidents appear to be the biggest factor in ensuring that the UK will never get rid of the Queen!
The US President [and Presidential Heads of State in general] seem to require so much gear to get them from here to there that its a first class case for actually creating a monarchy from scratch!
Poor old Queenie [Lizzie 2] has her own helicopter, which she paid for out of her pension and can call upon some aircraft of the RAF and British Airways when they have been brushed out and polished [never more than one available].
They take off without any ceremony from the nearest available airport without air exclusion zones that ground the fare paying public and leave them in their lesser aircraft fuming as their
45 minute reserves are burned off.... and usually without ceremony.
Indeed the US Presidents announce their impending presence by the very announcement of air exclusion zones ..... [is it safe?]
Any yet the Brit Head of State seems to manage to get around the world without undue fuss, still has an old railway train set of carriages, a couple of Rolls Royces and a Land Rover ...... She even sneaks around London wearing a headscarf and wellington boots....
Now how many 747s and helicopters does it take to move a President?