Undergraduate Degree in Business Administration vs. Top MBA in Europe

I've an undergraduate degree in Business Administration on a Top University in Europe. Is there any value (besides networking or access to jobs) in the MBA academic experience (Business knowledge) for example in INSEAD or LBS MBA itself? My primary Goal is to learn more and deeper business knowledge in general management to become a CEO of a large Company or to start my own tech company and scale it. I can't understand how the people with different backgrounds can learn more valuable things in 11-14 months which we've studied for 3 years at the University in St. Gallen. If I compare the undergrad wages vs MBA wages there is a huge difference. Can someone explain me why? The MBA curriculum looks very similar like our curriculum in undergrad. Thanks very much!