Realistically, balancing freedom and protection, lack of resources and demands that tax cuts are made, not investment etc etc banning the most dangerous breeds is probably the only option. I looked at the Calgary model - unfeasible and expensive, probably why it has been watered down immensely. It also seemed to work OK until hurricane Katrina brought in a huge influx of pitbulls. Once they were a bigger percentage of the dog population it was back to bites and maulings.
Tightening up on licences for breeders tends to favour big scale operations. I don't want a puppy from a business. I want someone that breeds every few years, they seek out the best mate well in advance, get their dna checked, they are brought up in the house, handled by the grandkids, are devoted on for 2-3 months, have the best food, best toys,are on lifetime contracts.
Dog licences, well the already responsible will pay, criminals won't. There are no resources to enforce what little we have now, certainly not to police any extras
Most attacks take place in the home, so muzzling does little to protect people (probably will help attacks on other dogs, but again it is concentrated on a small number of breeds, do we restrict the rights of everyone because people choose awful dogs?)
We don't have solutions for any type of crime if the perpetrators either take prison time as an avoidable part of the job, or just go around in a permanent state of belief that they are somehow special and their actions will never lead to harsh consequences.
Like guns, sometimes you just have to do your best to try and make sure that idiots find it difficult to get hold of the ones that are most lethal. Breeds that were designed for bloodsports fall in that. There are hundreds of breeds not selectively bred so that they can bait bulls and win. And it probably does mean that the law plays catch up.
I don't think we can say that BSL doesn't work because we haven't truly tried it. XLs are a pitbull crossbreed, they should never have been in the country. Pretty much every dog involved in a fatality was already known to the police, we should be less lenient and take dogs away far quicker, whatever the breed.