Way way waaaay back on release (or was it in beta?), there wasn’t any hero limit. You could pick 6 Winstons and go full monke on your opponents.

Then they made each hero unique, but you were still free with comps. You could pick 3 tanks and 3 healers, or 5 DPS and a poor tank who’d get flamed for letting his team die.

Eventually they settled on a fixed 2-2-2, which was extremely boring and basically killed any kind of interesting strat or just fun play.