I think the inflection point between “startup” and “bureaucracy” (which is not a bad word, just a term for organizing people) is role specialization.

Early stage everybody wears 10 hats, work is distributed and prioritized on a day to day basis.

Once you have dedicated people or teams for task domains then the whole thing shifts to having a need for bureaucracy.

You can slice the number of pizzas anyway you want, but imho once people have a “this is/isn’t my job” mentality (which again, is not a bad thing), you really need to focus on role boundaries and coordination. But the “startup” part is in the rear view.