Mine have automatic time limits on screens but certainly they aren't banned, otherwise DH and I would surely have to BSN ourselves too, or by hypocrites, given they are not an adults only thing and the kids, not being stupid, know innately what falls into that category and what doesn't.
Also I agree - sometimes all 3 of mine play Minecraft or similar together on the X box split screen, in the living room and have a great, cooperative, sociable time with lots of laughter. Also the case when they have friends over.
We go away for 2 weeks, during which time we do sea related things.
The rest of the holidays mainly centers around them having friends over, playing out, and I take them to outdoor pools as much as possible - the biggest local one they always bump into or arrange to meet friends at, but I also have free access to a smallish basic outdoor pool in a nice setting at my work, and if we go there in the morning we're often the only ones there, or nearly.
They have friends over as much as they like on days there's an adult home all the time, or I'll drive them wherever they want if they've made plans to go to friends or meet friends at the pool or in town during the day.
Sometimes we go for a low key outing just into the nearest bigger town for an ice-cream by the river - it's a beautiful town, which makes it easier!
Occasionally I'll take them out for lunch at a cafe where we can sit outside, but eating out is fairly expensive locally.
Sometimes the older 2 go on a bike ride together, or/ and I'll go with the youngest - I can't keep up with the older 2 
Most Friday evenings a bunch of pre and early teens including my older 2 meet up on the football pitch in our village or the one in the neighboring village and play football for 2-3 hours. They're doing this already, started in late May with light evenings and will hopefully continue all summer. Luckily we live somewhere this is wholeheartedly approved of by older adult neighbors and parents of smaller children alike,not somewhere full of purse lipped grumpy people! We're the closest house to the football field anyway!
We also go for exploring walks in the woods for shade - were outside the UK and summers are a bit hotter on average (tends to hover around 30°C )
I work shifts and do leave the kids alone - my eldest is 14 - though DH and I work it between us so that they're not alone for more than 4 hours, and probably only a couple of times per week - mostly I do lates / nights so they're only alone an hour before DH gets home. When there are no adults home screens are fair game.
My secondary age kids cook dinner one evening per week anyway when I'm on lates or nights (DH is home but mostly does freezer food, which he'll do once per week too) occasionally they cook when I'm home too, and usually once each on holiday - I did teach them, I'd better remember to teach dc3 sometime!