I'm trying to fix the geometry of the inset faces on the pillar after I used the "shade smooth" option. I added the Subdivision surface Modifier and the Bevel Modifier, but still the faces which are inset into the pillar, look bad. The inset faces should be with sharp corners all the way, meanwhile I get this. I also tried the Auto Smooth option instead of Bevel Modifier but no change there either. All transforms (incl. scale) after creation are applied. I'll be grateful for help.
It's because of your topology. You have given a Subdivision Surface modifier to your object (which may be not necessary by the way) but with the current topology it rounds these slots. To keep them square create this edge loop with the knife tool (K to activate, A to cut orthogonally, C to cut through). You also need to get rid of overlapping vertices with a Merge operation.