I think you are not comfortable with this trainer and therefore shouldn’t use that person. I don’t think every dog needs a prong collar or an e collar. I have one dog I NEVER use an e collar on, because it shuts him down (and that’s just the vibrate) and that’s not the point of the collar.
I have another dog I use an e-collar on at least weekly. That said I rarely actually press the button and almost never shock him, but it is there to reinforce his excellent, well-proofed recall, just in case. We live on an acreage next to a highway. The other reason is if he decides to go after a chicken. He knows not to, but is high drive and every once in a great while he just can’t resist a running hen.
Other than distance work I don’t use e-collars much at all and not to teach a new exercise.
That dog wears a prong in public too, but it is a back-up to an already trained behavior again. I don’t need one on my much “softer” dog. I use whatever tool works best for the dog and the situation.
My only general rule is I don’t like choke collars for my dogs, use them in AKC, but in general will use a fur-saver instead. Ymmv.
I use almost 100% positive reinforcement for training new behaviors. I introduce some negative reinforcement when the behavior is understood. Negative doesn’t mean agressive correction either.
This is just my way, not saying everyone needs to do it that way.