Luckily, no one has ever seemed offended when my little dog has approached theirs to say Hello. Sometimes they'll say "oh, he is old and grumpy" in which case I'll say "no problem" and call mine away. What's the big deal?
Just don't really see the big deal. It seems like a small minority of dogs that don't want to be approached (perhaps old or not well socialised?),
I have an reactive dog, he is nether old or was unsocialised, he was attacked 4 times by 3 different dogs in a short amount of times, we were very unlucky and everytime he was on the lead, so that has meant we have had to do a large amount of work just to get him on a lead.
The problem you are going to face is, if your dog walks up to the wrong dog and gets attacked then you are going to face having to do months worth of training to get them back to the way they were and there is no guarantee that will happen. So you are potentially creating a problem for yourself.
Also keep in mind that if your dog approaches another dog on lead and gets too close, you are trigger stacking that dog and potentially making it go over its threshold, doing god knows how many months of training for the other owner
During the day, my dog wears a big fuck off yellow coat, a muzzle and is walked on a short lead and I still get owners, like yourself, with off lead dogs coming up to him and then its my fault for him reacting. We have also been known to walk him at 5am and at 2am, just to avoid all people,