why are AAA devs so averse to the idea of making smaller, shorter, lower budget entries for their popular and otherwise unused IPs? why does every game have to be 45+ hours of main story with 60+ hours of extras that absolutely nobody is going to finish because the gameplay will invariably get stale?

1. Feeling like they need as much manpower as they can get for their bigger titles i.e. "the mines"
2. This is a big one, internal investment matters i.e. someone in the company with authority actually wants to make the game as a passion project usually because of some sort of sentimental attachment either through past work history or because they were a fan.