Does one really have to go work there for a few years? Aren't there other ways of immersing yourself deeply ?
Also to say no apps or games will be able to hit it big... Well, just look at Pokémon Go.
The reason it worked is because Pokemon itself is about traveling to different places and finding rare pokemons. That's literally the app - there is 100% congruence.
I think it also helps that Pokemon GO simplified the experience from Ingress which makes it more accessible to a wider variety of people.
Side projects.
Finding a co-founder/business partner with deep experience in the industry. (Worked for me.)