As someone who tried to develop a Unity game on a big team, it was hell. The collaboration is horrible, there are conflicts all the time for no reason. Simply getting the source, running the game and updating would produce conflicts. We also had to buy the cache licenses to make it somewhat workable.

But the worst was the support. It was worthless. Anytime we would open a ticket, they would simply google and return us links to forum threads that didn't address our issue. When we asked about missing important features or bug fixes, they told us to buy something on the asset store.