Are three or four levels enough for any CRPG or RPG? Why so many levels? After all, the fewer levels the easier and better, right?

I have read that the BG3 Early Access is going to have a four level limit (or cap). And, the final release version may have a 10 level
limit. However, why so many levels? You only need three levels. You have the beginning level, intermediate level, and advanced
level. A few levels is much easier to program for and develop in a CRPG. Why not program into those three levels all the
spells, feats, and bonuses?