Probably not for narrowbody flights, but it would matter for international. AF uses some of these gates at CDG, and they have a bank of 3 or 4 (I can't remember exactly); that helps mitigate both the delay in the gate itself and the delay in "people are really awful at scanning bar codes". The jet bridge doesn't seem to get overwhelmed, but they're also boarding through both L1/L2 and filling both aisles inside the A/C.

i agree 2 is plenty for a domestic short haul narrowbody.