They hype it up because it works. Half or more of big games budget is marketing, and they make it all back with a good profit.

Exactly. The hype is always bs because in big studio it is literally marketing's job to embellish/lie to generate hype and sales. Without a marketing dep you will only hear about games through word of mouths which imply the game made it on its own merits.

I wonder how much money was wasted on that Imagine Dragons song, that literally no one cares about now, that should have just been put into development.