I know what you mean, it doesn't reflect my view of the typically mocked middle class life, which I think is actually the very upper middle classes (yummy mummies, organic fair trade coffee sold by an independent, sourdough, rare breed meat, quinoa, mindfulness, sound baths, reformer pilates, lululemon, English sparkling wine, pickle ball, environmentally friendly second hand designer clothes, wooden toys, a hamper from Fortnums, glamping at Feastival, Daylesford farm shops, wild swimming) but I think "middle class" is incredibly, incredibly broad and to a lot of normally middle class people Joules, dishwashers rather than washing up, over priced cafe rouge and badminton followed by a walk in the woods with a Starbucks latte hit that bill. CPs don't dooriginal working class holiday park things, like "entertainment" like Butlins which is very classic old school working class holiday. They also don't have caravans they have the "wooden villas/lodges". There's no karaoke, no gambling/slot machines or arcades, there's a lot of wood and whilst the restaurants are chains now, they aren't mcdonalds or KFC, they're Starbucks, Bella Italia and cafe rouge.
I also think the clientèle at CP is super super broad, the sports bar is always really busy, always, so whilst I'd never associate soft play, tv screens and carling with middle class life, clearly lots of CP customers really want that.
The reality is the organic eating, farmshop visiting, range rover driving, designer coat wearing mummy and daddy middle classes are all skiing in Val D'isere, getting winter sun in the Maldives or having a luxury villa holiday in Arrabella and Rupert's Provence villa over the summer. So there isn't actually a proper middle class market. You could try Lakes by Yoo in the cotswolds, they're very traditional upper Middle Class (complete with £500 a night piece tag, Michelin star chefs doing supper clubs, a Barbara sturm spa and electric car charging stations).