As I see it, the MBA could means different things to candidates at different stages.
The person who wrote my recommendation matriculated after 9 years of work experience and used the access to faculty and resources during the MBA to think through various business models and eventually launch a startup.
For an early career candidate, the MBA could open doors, earlier, to opportunities that he/she might not have had access to. [Here, I don't refer to compensation, but beyond that, am referring to specific assignments that are more challenging or entrepreneurial]
In many ways, the Class Profile on the website, with an average of 5 years work ex. can be a great heuristic -- but only just that. The candidate can best assess when they are ready, and based on their profile/stage, what they realistically hope to get out of the program.
As for me, a college senior, I've deferred at admit at Sloan by 2 years -- which I see as the sweet spot for my specific case