It's not hard to imagine. A week at a beach resort for me will mean packing 2-3 pairs of sandals, 3-4 bikinis/swimsuits, 5 day dresses/kaftans, 5 dresses for the evening, a cardigan, a hat, 5 books, shampoo, conditioner (the hotel provides it but I like my own!), styling products, make up and make up remover, skincare, sleep headphones. DH and the kids take 4-5 pairs of shorts, 10 t-shirts/shirts, 3-4 pairs trunks/swimsuits, hats, books, medication, inflatables, sliders. And then we all take a couple of pairs of pjs/sleep tees and probably 10 pairs of underwear. They'll take socks as well, I'll take a couple of bras. I think that's about it, but it adds up to two cases each weighing 20kgs, or three lighter ones in my previous experience.
Of course some people hate the idea of that kind of holiday and some people would pack much lighter for it. But I like to wear different things day and night, I like everything clean and fresh on, I like to read physical books - and I read a lot on holiday! - I want to spend a week relaxing by the pool or sea with everything I want on hand.
If I was backpacking for three months, I'd do things very differently. I have! But it's easy enough to imagine packing differently and taking different types of holiday.