One of the reasons for arresting someone is to prevent an offence or breach of the peace (BOP) happening in the first place.
There doesn't always need to be a charge as a result of an arrest and you can't be 'charged' with a BOP anyway. You can only be placed before the magistrates court who can 'bind over' the person to try and prevent a future BOP.
Very few arrests for BOP result in someone being placed in front of the magistrates court.
Usually the person is detained for a few hours until the prospect of the BOP is averted and then they are released.
Here's the reasons why police can use their powers to arrest... you may notice that 'to charge someone' isn't one of the reasons!
I have highlighted some of the conditions that may have been more relevant to this weekends policing activity.
Again ignorance is a common issue when lay people comment on the police/ law procedure.