> Competing on price is something all business do anyway
Not if none of the competitors do, that was the point of the comment if they all think the competitors aren't competing on price then it becomes an informal price fixing scheme.
Exactly, and there are plenty of examples within the tech industry. Apple/Android app store fees didn't end up at 30% because of ruthless competition that drove margins down to almost nothing. If a market is controlled by a duopoly the two parties can easily keep prices absurdly high and everyone else has to just deal with it.