people always talk about Nintendo controllers being the best ever

Actually, having fewer buttons can mean more weird combos, since it means you have fewer options for attaching a given action to a single button press. You see this a lot with console ports of PC games that made good and efficient use of the keyboard: Quite a few actions end up mapped to things like "hold R and press X," just because there aren't enough buttons to cover all of them without invoking combos like that.

The flip side, though, is that having more buttons available means mappings become more arbitrary and less intuitive, which I think might be what you're actually getting at. If you're playing Super Mario Bros on the NES, A is jump and B is run/fireball. This makes sense, because A is the easiest to reach and jumping is the game's core mechanic. If you're playing Super Mario Bros on a controller with buttons for A through H, though, it's anyone's guess which button ends up being jump and you're less likely to see similar controls between similar games. Standards can still arise (WASD for keyboards being the best example), but it's messier than if there are relatively few buttons available.