You need to get over the fact we left the EU. I know it was a shock to you but please get over it. I never said that EU laws were useless, many of them were very good and most have been adopted and adapted by the UK ages ago. So the B word has nothing to do with people using UK law.
It's nothing to do with that. Read the link - you have to complain to the Airline, like Weststander did:
Back in 2010 after the Iceland ashcloud I claimed about £3000 from Monarch - took ten months but got there...
That one wasn't cancelled due to the weather though?
Maybe cancelled because Easyjet planes or crew are not in the right place due to previous issues?
https://www.moneysavingexpert.com/travel/flight-delays/
You should find out the reason for those cancellations and use the online Resolver...