Playground Rooms

So, while on a walk outside today, a friend and I were talking about playgrounds in general. So, the topic of League came up, and I thought "Why doesn't League have any rooms like this?". So, why not just create some little rooms, maybe the size of a base in League, furnish it, theme it up, and make it a sort of "Playground Room"? Essentially, people can join other friends' rooms by having their friend give them a key (password) to the room. Then, they choose a champion that they own and just enter the room.

Maybe it would cost 1000 or 750 RP to create a room, and a certain number more of RP at the end of every week.

This has probably been brought up before, but give me your thoughts anyways.