My son is 9 and has been in wineries, bars, fancy restaurants, airplanes, trains, etc. He’s seen a LOT more of the world and experienced a lot more than I had at his age.
The “leash” days were from the time when he was a toddler and walking/running until he was about preK aged.
Where many people had their kids in strollers/wagons, etc as a toddler? We had a nifty little insulated backpack with a leash attached to it that clipped at his chest. He couldn’t wander off and get hurt - and he learned that Mom wasn’t a pack mule to carry his stuff around either
Zoo, aquariums, festivals, boardwalks, etc - the kiddo and I went to all of them real simply with me wearing a backpack and him wearing his backpack and go see and do whatever.
He learned by walking right next to me and us constantly talking - even when he would just be babbling along because he didn’t have verbal expression at that point - or was using his communication device.
Wagons/strollers, etc couldn’t work for us because my son didn’t have expressive language. We relied on the ability to have constant eye contact/use sign language, use facial expressions and body language. He understood ME - and I understood him.
Every parent has to find what works for them.
But I’ll never understand spanking and hitting a kid. I just don’t get it.