It definitely is a real problem, although I cannot say with certainty whether it's a significant enough problem to make curbside lanes worse than roadway lanes.
The global consensus on which type is safer is not nearly as clear as you confidently make it out to be.
A lot of things need to be true for a curbside bike path to be safer than a roadside one, most importantly protection against dooring and ensuring visibility at intersections. If these measures are not taken, the result is often less safe.