Shoes standing on the floor collect dust around them, and vacuuming underneath means moving everything first. A rack fixed to the wall leaves the floor clear from skirting board to skirting board — a robot vacuum passes straight under, and a damp cloth does the rest. The sightline along the floor stays unbroken, which is what makes a narrow hallway read as wider than it is.
A floor-standing shoe cabinet wins on one thing: hidden capacity behind doors. If you have the floor to give and a household of shoes to put away, that is a fair trade. In most flats it isn't.