There are a way more local multiplayer games on the switch. More titles aimed to kids as well.

If you are worried about the Switch getting damaged, you can dock it and lock the attachable joy-con controllers away, then the system would only be used as a console and not handheld. You would have to buy three controllers for the kids though.

I would ask your oldest why they asked for a Switch, it is possible their circle of friends play on Nintendo and they would like a system that would let them play online with friends.