If "lunging" was the only thing knife welding psychos could do the world would be much nicer place.
(There used to be an excellent police blogger who talked about doing this from firsthand experience, but he was de-anonymised and his blog taken down).
Believe me no-one wants to try and tackle a knife wielding suspect with a baton, at that point you're using defensive tactics and your partner will use their CS/PAVA to try and disable them.
Fortunately, in the UK, the vast majority of people with knives aren't actively homicidal at the point at which the police turn up.
Nightjack was amazing, the Times is in my permanent bad books for their nonsensical justification for outing him. He thoroughly deserved the Orwell prize that he won for his blogging.
For others reading this, there are a lot of good videos on the net showing examples of it.
The qualfiied officers are Authorised Firearms Officers who will also stand up the equivalent of SWAT teams as needed for each constabulary.
London has Specialist Firearms Officers as well who are a standing set of SWAT type teams. Several have written some very good books about their experiences, Steve Collins especially.
The main thing in the UK is that armed officers who discharge their weapon, let alone kill someone, face extremely rigorous scrutiny by an external agency. This combined with no specific legal protections means that a police officer shooting their weapon is very rare, it happens a handful of times across the UK each year.
Yes, talking people down works in every situation.
Not to say that guns work every time but if someone has the intent to get all staby It's time to go lethal.
I think it would be eye opening for everyone to get a taste of how things can go wrong in police situations themselves.
I think in some ways, this is a result of our fondness for the second amendment rights and arms as well as accepting the police as a necessary force to keep the peace.
I'm not sure if there is an easy way to de-escalate things. We might start with police 'engagement' procedures standardized from a federal level --but there'd probably be pushback from the states.
I do have a quibble with _always_ presuming innocence. If you see someone in the act, then I think they can take action without such presumption.
One of the specially hard things for me to understand is the necessity to shoot at 'disturbed' people wielding knives. Yes, I know knives are deadly --however, knives don't travel very far, compared to firearms, why not back up, give them a safe distance and try to de-escalate before shooting at the 'lunge.' Again, I know most of those disturbed people do mean harm[1], but you can avoid their intended harm by giving them space.
[1] Some intending assisted but unintended suicide from the police.