All true. We're in Salcombe quite soon and there are two gated entries on the coastal road there, which would have restricted 4x4 use, but the council have lost their resolve, because only one bollard survives at each gate, and the kerb has been rounded at the other side. Car size could be managed by width restrictions, or height restrictions in car parks and around schools, but it would be very unpopular. Freedom of choice blah blah.
Funny thing about width, speaking as an ex MGB owner - on narrow Devon lanes I was often squeezed really hard, by oncoming drivers not slowing at all due to the narrowness of the MGB, whereas in a more normal width car, the other driver has to slow down.
My drive is narrow so I'm limited to what I can get down anyway, which is no bad thing.