I don't agree with muzzles for every dog - mine is about 30 cm tall at the withers and weighs about 5kg. I doubt very much she'd bite (because of her temperament and training) but even if she did, it would not be likely to cause serious injury.
The issue is with they type of person who owns poorly trained, large, heavy, powerful dogs, especially if they want it to "hard". Banning by breed hasn't really worked - as the next "hard" breed comes trotting along. But requiring muzzles for certain types of dog over a certain size might be a good safety precaution - but hard to police (the actual police being pretty damned stretched already and no council likely to have the cash to augment dog warden services)
There needs to be a change of attitude towards dog ownership - I don't know how that would come about though. Good owners already have well-behaved dogs , because they look after them, have trained them and are generally not a dick. It would need a hard look at who the problem owners are, and then working out how to deal with it (education and/or sanction)
PS: whilst typing, I got a pop up saying government pledges to ban American Bulldogs by end of year.