There was a very good rule change recently: if a game goes to overtime, all teams can do one more exchange. This allows teams to safely use up their regular 3 changes without having pressure to save one change for a possible overtime.

But watching "friendship" games between national teams where often there are much relaxed change numbers (these games are the one opportunity for the national trainers to experiment widely with the team setup), they tend to be pretty bad. Changing the compositon of a team strongly has a huge potential to be very disruptive. This shows how much football is actually a team play.