Leaving loads of stuff behind is unhygienic and also puts a dampner on the next guest' 'just arrived at our holiday house' vibe. If you don't want things to go to wastetake them home with you; no one else wants leftovers.
My thoughts exactly. I hate it when there's all manner of opened packets, and cartons, including salt and sugar. We never use any of it as there's no telling how long it's been there, whether it's been stored correctly, whether there's been insects in it, etc.
Some owners have the right idea and leave a few sachets of sugar, coffee, etc., and a small carton of milk. You can use them or use your own and it's enough to get you started.
We stayed in a horrid place once where the kitchen cupboards were full of all manner of other peoples' rubbish, including several packets of cereals, half used packets of pasta, - all of which were at least a year past their best before dates - the worst being a tin of prunes that was 10 years out of date! Then in the sugar bowl were some dead ants.
There's a difference between leaving some basics for your guests as opposed to being too bone idle to clean the place and dispose of the rubbish left by others!!