I'm not fundamentally opposed to the idea but frrom a practical or administrative point there would be an awful lot of permits or licenses should such a scheme be brought in. Practically every tradesman uses a knife of some description even iff it's only a retractable Stanley knife and they have been used in assaults . How about kitchen knives ? Cooks and chefs would almost obviously need a permit but how about the average person who takes a knife out with them for the yearly family picnic? Hobbyists of course , for fishing , camping , re-enactment and anyone who carrries one because it may very come in handy.
But does licensing all the legitimate users stop those who would wish to use a knife/tool for the wrong reasons? The argument seems to work with regarrds to reducing the number of guns available for instance , society could continue without guns but the humble knife is such an important tool that if it were restricted or took away we'd really struggle.Harrsher punishments and restrictions on the purchase of knives has seen things like acid being used in place. Restrict that and it'll be hammers or big spanners or screwdrivers or tree branches...
With the recent airport problems there has been a call to license drones which may be the right way to go but there will still be those who will build their own in just the same way as there are people who can and will make their own knives. Only the other day I watched a YouTube video of someone making a knife out of a file . That was just with an angle grinder , no forge work . It certainly looked the part although I was unsure about it being too brittle but that's another story.
I'm not even going to pretend to know how to approach this that won't leave at least part of the population feeling pissed off or ignored , can't please all of the people all of the time and all that.
Seeing as this post mentioned knives and other bladed tools such as axes I'd like to say I'm more of an axe person than a knife one. I do carry my SAK but feel more comfortable using an axe than a large knife . Probably comes from being a site joiner for over 30 years where a lot of work was done with an axe. Shaping , defrrazzing and scribing for instance and I've even eased a door with one and an axe doesn't have to be swung . It's possible to use an axe for really quite delicate jobs too.