Investment-driven development. When it's no longer about creating something compelling, but about convincing the investors that banking the production means a fairly safe ROI, you stop getting creative works by auteurs and you start getting sequels, remakes, and low-stake, inoffensive, mediocre, forgettable, bland sludge. At the upper end, investors give directors checklists and guidelines to limit their authorial voice. That's why it doesn't matter who the directors of the MCU movies have been. They're just Disney-produced movies. A film student could have directed them and it wouldn't make a difference.