We don't do expensive holidays.
Typically we choose a last minute deal, eat out perhaps once, or get a takeaway and take picnics for lunch, and spend most of the time on the beach where wall we pay is car park and ice creams. There's 5 of us-3 teens and me and dh.
This year we got a cheap Pontins: Not sure I'd recommend it but we paid approximately:
Accommodation: £200
Food: £175 (supermarket shop on the way, eating out twice, both times under the 50% scheme and one takeaway fish and chips)
Daily cost £15 most days (£5 car park, ice creams for all)
Petrol £40 (inc there and back)
Total: £430
We ate out twice this time and had a takeaway partially because the accommodation was so cheap so we felt we could justify it, and partially because of the 50% scheme.
The cost to me that stands out is the food, which is totally your choice. You can say you didn't eat anywhere expensive, but maybe you are including breakfast at the hotel, midmorning snack, lunch at a nice hotel place, and evening meal at a restaurant.
The year we stayed in a hotel we bought our own breakfast (croissants), stopped at a supermarket on the way to buy sandwiches etc for lunch, and then ate out, and between the 5 of us, for 5 nights we would have paid less than half what you paid.
But we'd have eaten takeaways on a couple of the nights, we ate out twice at the same place because they gave a us a discount card (and it was especially nice) and the other place we ate out was a nice pub.
So part of that is your choice, so you can't do that and say "holidays in UK are expensive". It's a bit like saying buying a car is expensive:
Person A says "yes, I paid £30k for mine because there's no point buying one second-hand"
Person B says: "Yes, I could only get a 5 year old car for my budget of £5k"
Person C says: "They're not expensive, it's important you get good quality because of the safety, it was £10k well spent"
Person D says: "No they're cheap, mine was £200".
They've all made choices on amount of money to spend depending on their budget and what they want.