Ok so I'm a manager so I obviously have a bias but throwing managers under the bus for AAA crunch is sort of not fair. Majority of the crunch I've seen or heard first-hand account for are not planning errors. Here are some thoughts https://twitter.com/tha_rami/status/1335726241119424517
First, even a producer (or whatever else you call the person in charge of the project) is not in charge of scope entirely. There is upper management and what they want, what marketing has already promised to fans also directors.
Secondly, a lot of crunch happens because directors are allowed to do crazy stuff. I've seen more than a few projects burn the first half of their timeline "figuring out the game" or directors deciding they're not happy with the end result and iterating on final polished content
The consequence of this always falls on the team having less time and resources than they need.
Why don't producers fire these directors? Well, it's not that simple. Directors like this are frequently more powerful than the producer. You have studios founded by Director types and I've also seen a Creative director pushing out a producer he didn't like
Crunch is a systemic issue and a cultural issue. Unless top management, production management, and content direction agree to not do it it's not something a manager can resolve.
Frequently when a manager tries to push back alone they're going to either get pushed out, burn out, or eventually give up and quit.
Crunch is bad and I totally agree that it's a product of the failure of management. However, 'crunch = bad' producer is an over implications of a systemic issue.