Yupand there lies the issue. If you have the choice to bail after 2 hours then a and e isn’t the place for you.
Also the fact that the reception area seems slow isn’t an indicator on what is going on behind closed doors, there will undoubtably be allot of seriously unwell individuals arriving by other means…
IIRC most hospitals these days have the ambulances arriving through a separate entrance to the public/walk in A&E one, so they might be getting a steady stream of people straight through to the A&E beds whilst as far as the public in reception are concerned there is nothing visible going on.
Brother in law was a "self presenter" at A&E after a very nasty work accident (his brother drove him there as they worked together about 10 minutes away at normal speeds), apparently he was intercepted pretty much before he could reach the reception desk by a nurse who spotted his arm looked very wrong.
When my dad had to go in just before Christmas I took him in by car and as soon as the nurse started to take his stats he was whisked away.
Something I have noticed is that my preferred local hospital has both an A&E and a "minor injuries" clinic, latter can be almost empty whilst the former is full and the receptionist nurse is trying to get people to go to the MI.