Lets have a gameplay mode where we can play on old patches
It would be really fun to just play a season 1 or 2 game as a temp game mode. Obviously visual updates don't have to be removed but to have the same balance, items, champs, etc as they were would be fun.
There are certain champs, items, and tactics that just aren't usable in any given patch and it would be great to be able to go back and play what you thought was fun about old iterations of the game from time to time.
This would also allow players to face the reality of previous balance states. Nobody could lie about "season 2 being the most balanced" if it was playable right now.