Not true at all... the prongs on any plug are live just a few mm in.. not a few mm out. This is why it has recently become good practice (but not code) to mount 3 pronged outlets "upside down". That is, with the center ground pin "up" (upside down face). This is to prevent a short if the plug is partially inserted and an object slides down the wall at hits the prongs... it would only hit either the common or hot , as well as the ground... but not both hot and common.
That's not upside down; that's the right way up.
Americans are really strange. One of the strangest things about them is that they think they are the standard by which normality is measured. What you say may be true for any US plug, but it isn't true in the developed world.
From
Wiki:
Pin insulation
Initially, BS 1363 did not require the line and neutral pins to have insulating sleeves. Plugs made to the recent revisions of the standard have insulated sleeves to prevent finger contact with pins, and also to stop metal objects (for example, fallen window blind slats) from becoming live if lodged between the wall and a partly pulled out plug. The length of the sleeves prevents any live contacts from being exposed while the plug is being inserted or removed. An early method of sleeving the pins involving spring loaded sleeves is described in the 1967 British Patent GB1067870. The method actually adopted is described in the 1972 British Patent GB1292991. Plugs with such pins were available in the 1970s, a Southern Electricity/RoSPA safety pamphlet from 1978 encourages their use. Sleeved pins became required by the standard in 1984.
It has been commonplace in the UK since the 1960s, and mandatory for the last thirty years, to design plugs in this way.