Every 2 years is too much. As you implied, it's an event that has to be a build up of anticipation. You have to miss it. No way it would feel memorable with so many world cup songs along the way. 4 years feels like forever. It's why it's great.

Though, I disagree that it would be boring to have 48 teams. Perhaps for those who always have their teams represented, such as the Europeans, but for everyone else, it would be a dream and surreal to see their national team in the biggest sporting event. On top of that, it would also feel a lot more like a "World" Cup. Ask FIFA why they expanded it from 16 groups to 32. Same reason. Imagine seeing all the different flags, different cultures, different playstyles, different songs, all coming together. Surely you must be tired of always seeing the same EuroLeague players.