I honestly think that young children prefer being at home with their normal routine, but I agree that things do get better as they get older. Our children take books, paper and crayons, sellotape, scissors & glue, also card games & small toys eg Playmobil people. It's amazing what other stuff can be made from scraps/how you can improvise if you have the basics.
This year we went to France, but they accidentally left behind the toy boat & the Playmobil they were going to take. However, we found one in a supermarket full of Breton biscuits, & once we'd taken them out they could sail it, using a few Playmobil people we'd bought from the supermarket. The biscuits came in handy for snacks on the beach! We also ran out of reading books, but managed to find a few children's titles - a very odd selection! - in a French junk shop, which was an experience in itself as they had great fun examining the other artefacts on sale!
Last year we found a Fimo kit with clay, paints and varnish in a charity shop, and they made some figures to go in the plastic lifeboat they bought in the RNLI shop in the village where we were staying.
Our worst experience must be the year we went to a holiday cottage near Shrewsbury with dd aged 8 months and dsd aged 13. We were also provided with a cot that looked as though it wouldn't have been out of place in a Rumanian orphanage, although when we told the owners that we were concerned they went out and bought a travel cot. Difficulty with that was that dd had never slept in a travel cot, and that just made her more unsettled. Consequently she woke up every hour during the night for the whole week, and the only way we could keep her quiet & get her back to sleep without waking dsd was for me to feed her. However, instead of sleeping in, she woke up each day at 6am, and in order to enable me to catch up on a bit of sleep and not to waken dsd, dh had to take her out in her buggy around the country lanes of Shropshire for a couple of hours! There's one wonderful holiday photo that says it all: her holding a fluffy toy snake and beaming at the camera while he looks about 90 and as though he's not slept in years! Happy days!