In my experience dogs are less stressed without a leash. The primary reason for using a leash is that I feel compassionate about people who are afraid of dogs or don't like them. Seeing a leashed dog makes them feel more secure.
It's very annoying how people anthropomorphize and refuse to take responsibility for their animals.
Guess what, your dog isn't a person and if it gets agitated and attacks someone, that's your fault. If it decides to chase a squirrel he sees across the street and gets hit by a passing car in the process, that's your fault.
Barring all the worst case scenarios, consider that other people don't like your dog jumping up on them nor do they want it pissing and shitting on their property, which is what most dogs do if left to their own devices.
Often people who won't leash their dogs claim that the animal is trained well enough to not need it, but this is rarely true. In reality, such dog owners usually just don't care about others and will readily blame anybody but themselves when their unleashed dog gets into trouble.
It's a safety issue for the dog. I recently saw an off-leash dog get freaked out and run out into a busy road. (The dog didn't get hurt luckily, but it was a horrifying experience for all involved.)
Sure, your dog might be "better" than that. But it's not a risk I'm willing to take with my dog.
But using a leash is part of the domestication process. I can tell you I was at a national park this year, and two off leash pitbulls and a Labrador charged at me. If it wasn’t for my knowledge about dogs, I probably would’ve been bitten.
So yes, having a dog on a leash makes me feel less stressed.
I fully agree. Yet animal shelters are crammed after the pandemic. Adopting an animal can improve their live.