Some people think that the honk/beep is to confirm that the car got locked and the alarm got activated. So they will press the lock button until they hear the confirmation.

But it is a confirmation. If you're far enough away (perhaps you forgot to lock right away), you won't hear the lock mechanism and wont know if you are too far away for the signal to reach. So you wait for a honk.

That sounds like a feature looking for a problem... my car flashes the hazard lights when it locks, and I've been able to lock it every time without any problems. I just make sure I lock it when I have visibility of the car.

Exactly. Would you trust a computer interface that gave no indication it was responding?

I guess what I meant was that there are some models that will be locked by clicking only once, they won’t make any beep/honk (you can know they are locked because you can hear the locks), but if you click again then the car will make a sound to confirm it’s locked, I guess this is a feature, if you are far from the car you will know the controller signal actually reached the car. But a lot of people think pressing once locks the car and the second time is to set the alarm.

Light flashes twice, the mirrors fold. Visible at any distance.

The curvature of the Earth will stop you seeing the car from about 5 miles (assuming you're 6 feet tall and the lights are 2 feet above the ground.)

But are you really locking your car from 5 miles away? I doubt the radio in the key will be strong enough for that distance.

Hold my Pringles while I use the can they came in as a directional antenna.

It's not just "think" - some cars specifically beep in different ways depending on lock status. Recent-ish Fords beep once when locked, and beep twice quickly if a door is ajar and can't lock. It also blinks the lights to match, but the sound is much easier to recognize.

My Honda demands tribute when you close the rear tailgate. If you fail to provide the attention it demands, mainly waiting for the gate to fully close, it beeps 3 times and unlocks the car.

Very helpful feature.

Better than my Volvo that would lock the car when you closed the back hatch... even if the keys were in the ignition and the car was running.