The OP is simply pointing out that it is illegal for a homeowner to simply cut (lower) the sidewalk near their home so they can drive their car to park it on their property, without obtaining a governmental license to do so.
And if they do illegally designate an area of a curb as their private entrance to a non-official driveway, anyone can legally park in front of the sidewalk curb and block the entrance to their illegal driveway.