I so agree, Fifi. We are not dogs - grovelling and deferential animals who look up at humans and follow their commands. This just one of the many human delusions that we have to fight against. And it is very difficult to get the message through to them.
If they advance towards you with a harness, run and hide under the bed. If they pick you up with the idea of putting it on, wriggle hard and run and hide under the bed. If they hold you down and put the harness on you, run and hide under the bed. Refuse to come out for several hours. With luck, they will realise that you are not going to tolerate this senseless human behaviour.
A Siamese acquaintance of mine let her humans "train" her to a harness. They decided to take her and their caravan to Greece. On Brindisi docks, they let her out of the caravan in her harness and a sudden noise freaked her out. She wriggled free and nobody has ever seen her again. A warning to all cats not to let humans treat them like dogs.