We shoot a lot of MGs around here for funsies, and the BAR is actually superior as a squad weapon to the MG42 for several reasons:
BAR can be fired from the shoulder, while moving.
BAR mags were easily distributed about the squad to help keep the MG fed. MG42 used boxed and belted ammo, harder to carry around.
MG 42 has an incredibly high cyclic rate, which wastes ammo, and means that engagement time is limited.
The Germans had a SAW called the FG42 that was roughly equivalent to the M249, that fed from mags and was very portable. It was only used by airborne forces, though.