Going all mumsnet for a moment here-why so many snacks? And why has everything to be in tiny packages. Of course you need more stuff then. If your boys need so much food buy some bigger things.
And 45min screen time DAILY sounds crazy. I mean Jackson is 5? Especially on holiday. But where I am from screen time is handled more restrictive so this might explain the krass difference. I know enough three year olds that get 30min a week and maybe a three minute teeth brushing video.
I don’t see the problem with disliking kids clubs though. Many parents want to spend their holiday with their children and find a balance on activities catered to them (zoom pool, playground, beach) and to adults (hiking, museum, exploring…). Most children get along the more adult activities just fine if they are used to it.