FIRST.... the term e-collar is commonly used by veterinarians to refer to the Elizabethan Collars, and the collar you are talking about is actually a shock collar.
To be honest, I can see using the shock collar to assist in training a recalcitrant dog who doesn't come when called, but I also believe that positive training is more effective. My breeder trained my 2 sibling pups to come for treat when called and whistled for BEFORE she sold them to me at 8 weeks of age. And I continue that training even now that they are 10 months of age as they've reached their exploratory pre-teen age time.
I don't like using a shock collar for barking, but my dogs are pyrs and supposed to bark to scare away predators and intruders.
I have a shock collar and when my first pyr was a pup, I did use it to assist in training to come when called. Most of my difficulty in getting her to come when called was my own fault, for becoming angry when she did not come. Pyrs are sensitive, and positive training with treats and praise are much better than anything else. To be honest, pyrs are stoic and bull-headed, and they often will ignore the shock collar so it didn't help her much. I've worked years to undo the harm I caused by becoming angry at her when she didn't come when called. The shock collar only gave me a little bit of help.
I prefer personal training with treats and praise, and attending obedience classes with your dog to use of a shock collar. They are much more effective, and you don't want to get into the habit of using a shock collar to punish a dog for not obeying. Punishment and yelling usually make the problem worse as the dog is trying to avoid your negative behavior towards them.
My husband agrees with you about using it for no-bark training. I don't.
You probably live in a city or town. I live in the country where immediate recall is rarely critical.
Part of what has brought you to your belief in the use of the collar is bad experiences your friends and acquaintances have had. While sad, you cannot undo what they may have done wrong. It's sad that they never learned what would make their own dog respond as needed. A lot of people who have dogs don't learn how to get the dog to do what you want... and the best way is to find out what will get the dog to WANT to comply. That's the challenge. The price for failure can be very high and painful, as you know -!-