There's a core problem with software projects in that adding more manpower tends to result in a "combinatorial explosion" of complexity. The software dev way to say it is that project complexity tends to scale exponentially in the size of the team.
So just using fewer devs seems like a good solution - and it can be, in certain circumstances. Factorio certainly wouldn't have been made a better game if they'd hired an extra hundred people.
However, number of people still tends to be the limiting factor in terms of content. In order to make more content (graphics, story, levels, mechanics, etc) you kind of do need more people. Factorio is helped by being somewhat limited in content - I just mean the quantity, not how good it is or how many hours the average player gets out of it.
So if you want games like Elden Ring, GTA, Fallout, etc etc, you need to eat the cost in extra complexity because you need a big enough team to make the insane amount of content that a...