You misunderstood me completely. A "firm hand" does not mean cowing the dog by yelling, beating, and abuse. It means showing the dog in dog language what the boundaries are and who is master of the pack. There are books on this; read one.

Treats have their place, but you can't bribe the dog into being good. Often, it's this newfangled lovy-dovy snowflake bullshit that causes the problems in the first place.

A dog needs to be treated like a dog and not humanized. This is what the animal understands and thus it's what makes BOTH of you happier. Since the dog can't learn how to think like a human, you need to learn how to think like a dog. Do you see what I mean?