I wouldn't want a dog that I can't let off-leash... one of the reasons I didn't end up rescuing from the greyhound rescue, lol
Personally I have always let my dog off leash, aka go to the car, on the driveway without it, he can go quick pee without leash, etc.. at night I always walk him without leash in my neighborhood (side streets)... I had trained him lots of times without a leash on, so he kinda doesn't know the difference that he HAS to listen more with a leash or without one, if that makes sense?
I use positive enforcement, I worked on the recall from when he was little... always call him and and RUN, run, run the other way, always make him chase me and ensure I am way more fun than anything or anybody else.
Also right from the beginning that he is NOT to go off the sidewalk, ever, unless I say okay, including if there is another dog across the street barking at him... For example I say wait, everytime I cross a street, etc... when he was smaller and tried to walk off the sidewalk I'd be NO.. and run the other way, teaching him that NEVER go off the sidewalk, but to recognize it as a 'border'
OF COURSE I watch like a hawk, and if I see anything at all I use the command leash on.. which means come close to get your leash put on (always gets treats for that to ensure it's positive for him and it's not a trick) "Come" only use for no nonsense and when I know he IS coming followed by a sit in front of me... 'Come' is NEVER used for making him do something he hates.. like brushing or having his ears cleaned...
Now, even when he knows a person across the street and he is all wiggly and eager, he waits for me to say OK, 'Hussle' (means ok to cross the street, just NO dawdling no smelling)
I am NOT encouraging other people to take their dog off leash in city, just saying that I do, but I know I take a few risks with it... But for sure as soon as we get to a field, etc.. he is definitely off leash... I trust him, even if he was to get spooked to run to me, instead of taking off, I expect him to always come running to me. How else can I train my dog if you NEVER trust him?
Dunno.. just a few thoughts of mine