A: No that's not the use case always for all games.

When it comes to choosing between immediate feedback and leaderboards, it really depends on what you're trying to accomplish with your game or campaign & on which channel the game is published

You won't user leaderboard for following
* Limited-time promotions where you want instant conversion, such as flash sales or one-day events
* Quiz or trivia contests that are meant to be completed in a single session
* Customer acquisition campaigns focused on immediate sign-ups or purchases
* Website campaigns to boost signups & sales, where users don't visit everyday
* Promotional scratchcards or instant-win style digital games

You would use leaderboard when:-

- When you have prizes that will be awarded at the end of a longer competition period
- In mobile apps where retention is critical - daily score updates give users a reason to check back & easier for you to keep bringing them through push notifications
- Social media contest, where keep the buzz around contests live for a period of time & have prizes to give away in the end