That person ends up being the success or failure of the project. If they're doing a bad or mediocre job there's nothing that can change that course because you won't know that until it's too late. The flip-side is that it prevents 'design-by-committee' mediocrity and can allow people with bold visions to express those ideas.
I worry this might be a bad lesson to take. The success of some really big games has been because of singular visionaries that were able to keep going for what they wanted. Yes, it's true some of those people are hacks and idiots, but it's very possible to lose the vision of a game by making it a compromised solution between 15 different studios.
Bloomberg reports that newly-appointed CEO Takashi Kiryu is aiming to improve the company's profitability by whittling down the number of smaller projects it releases, while focusing on big-budget games with a higher potential to improve profitability.
So you're disappointed with the sales of these enormous games that spend far too long in development and don't get the return you want, and your plan is to double down on these games instead of Dragon Quest Builders and Octopath? Here's an idea: take someone who's successfully led a smaller game and then give them progressively larger projects to lead. And maybe don't make a main entry in your marquis series exclusive to a single console in an age where the PC market will likely outsell it.