I think the given example is really bad, Rocket League does free-to-play in one of the best ways possibles. I never spend any money on their IAPs nor do I care about them, I still feel like I have access to more customization/items than I have the time to use.
A "better" example are games that have the goal of progression (e.g. city builders, like Clash of Clans) and then simply lock that progression behind a paywall, giving you the option to either wait for hours or pay a "small" amount to skip waiting.
A "better" example are games that have the goal of progression (e.g. city builders, like Clash of Clans) and then simply lock that progression behind a paywall, giving you the option to either wait for hours or pay a "small" amount to skip waiting.