It's important to differentiate skills learned at big companies. Some are very useful, but others are coping mechanisms that have no place in a startup. Meanwhile, the scrappiness and well-rounded skill set learned at a startup will almost always have a place in larger businesses.

My own personal recommendation for early career workers would be to prefer the cream-of-the-crop mid and large companies where you'll get useful experience you can't find anywhere else, then prefer startups and leave the slower-moving and more dysfunctional larger companies as a last resort.