When I went into Jeff Sutherland's Scrum Master class, he stated that "The Scrum Master is the most important person in the team", on the Product Owner Training, I heard "The Product Owner is ..." - and during Scrum Developer Training, I heard the same about Developers.
Now, what is the real deal?
Let's look at this slowly.
The Product OwnerImagine you have no Product Owner.
Who takes care of the backlog, who grooms it? Who makes the calls when stakeholders quarrel about the direction of the product? Who communicates the product vision to developers and stakeholders?
Ok, let's make it short. If there is no product owner, there is no product, there is no project. There is no need for a team - so obviously, the PO is the most important person.
Well, that was quick.
The Scrum Master
Imagine you have no Scrum Master.
Who arranges your ceremonies, who takes care of impediments? Who makes sure that management or other stakeholders don't violate the team's self-organization? Who takes care that the Working Agreements are adhered to?
Ok, let's make it short. If there is no Scrum Master, teams will most likely fall into disarray. Maybe not because of themselves, but because of the world around them. A team in chaos will not deliver.
So, obviously, the SM is the most important person.
Now, we've got a conflict already.
But we're not finished yet.
Ok, in traditional organizations, we know that managers think that the worker drones are easily replacible but everything depends on their genius.
But let's get real: You got a product vision, you got a development process. But who does the thinking, where does the code come from? Who makes the vision real?
Guess what - if there's no developers, the best PO in the world is useless!
So, developers are the most important people!
Everyone is important!
Many agilists use the Pig-Chicken metaphor, stating that an Agile team should only consist of "pigs". I don't like this analogy, because first, I don't consider my coworkers to be pigs for obvious reasons.
Second, if you're in Saudi Arabia, chances are that nobody wants bacon, rendering the pig completely worthless.
Simply said, if you're on an Agile team, everything depends on your contribution. You are essential to success. If you're not essential, you're in the wrong team!