I think there's a pent-up resentment at having less cash than is comfortable, sky high rents or mortgages, difficulties accessing the things they see others having on social media. Add in drink, drugs, a hot humid night, boredom, and some rabble rousing. Being persuaded that rents would be lower, everything would be easier etc if it wasn't for 'immigrants'.
Their anger is not all unreasonable but their scapegoating and their way of expressing it is. We need a year of the new govt resolving disputes, a year of falls in interest rates and inflation to calm things down.
I'm not making excuses for it but failure to understand people's anger would be a mistake.