The neo geo has fighting games, and uses 4. I think every non-fighting game for the neo geo uses 3, with D button sometimes duplicating an A+B action?
You could probably get away with 3.
Here is the thing about buttons. 3 buttons and 6 buttons take up the same amount of panel width. The difference in cost between 2 players with 3 buttons and 2 players with 6 b uttons is about $9.
While that may be true, I physically can't play games with that many buttons. Simplicity is why I like arcade games. I am so bad at xbox, playstation, etc.
I'm with ya. I don't know why every game developer these days feels the need to use every single button on the controller.
I can handle the 6 buttons for street fighter because they aren't just random and completely different things.
3 types of punch on top, 3 types of kick on the bottom.
Aside from fighting games, I have little patience for games that use more than 3 buttons.
If I were going for less than 6, I'd do 3.
For the few games where you actually do need 4, the 4th could be mapped to a combo (mash all 3=4th button).
The only ones I can think of that would use 4 are the two Dungeons & Dragons games.
Not really saving any space, but mentally 3 feels a LOT simpler than 4 IMO.