But at a large company, how likely is it that a team is going to have their own AWS account AND have free rein over it? The two companies I've used AWS at both

But at a large company, how likely is it that a team is going to have their own AWS account AND have free rein over it? The two companies I've used AWS at both operated this way. In fact, each team has multiple product accounts (for dev, testing, production). So I don't think it's unusual at all.