I also enlisted delivery drivers as confederates in working on his fear of large motor vehicles! I'd explain that he was scared of trucks and ask if they were willing to feed him some treats from the vehicle. If they agreed, then I'd hand them some treats, go inside to get the dog, and then my dog and I would "discover" that the truck had a nice person inside who wanted to give my dog good things.
My dog loves cats, and it's not an accident. Even though I've never had a cat, I made sure to introduce my dog to cats when he was a puppy. I even made sure to introduce him to cats who were unaccustomed to living with dogs, and unfriendly or indifferent cats who didn't feel particularly inclined to tolerate him in their personal space, because I wanted him to learn to recognize and respect the signs of a cat's discomfort. (Some of that was ultimately undermined by time he spent in the company of my dog sitter's excessively tolerant cats, lol. He has arrived at the mistaken belief that monotonously barking at a cat is a good way to entice it to chase him, which can make him insufferable around cats who aren't interested in him.)
My dog is very small. He's never bitten anyone. But when someone at the park tells me they're afraid of dogs, I still make sure we keep our distance.
I'm sorry for the bad interactions you've had with dogs and the careless owners you've met who have subjected you to frightening or even dangerous encounters with their dogs. That's legit terrible.
But anyway I made an effort, sometimes more successful and sometimes less successful, to try to make my dog well-behaved towards every group you mention. Where I've failed to do so I manage him to keep him away from those critters and people who would rather avoid him. And I think even when people don't do all that, it's more lazy selfishness than it is hate.