Unfortunately, you can’t guarantee that Penn will develop maturity over what will happen at GT. Personality is typically something fairly hardwired by the time students enter college. Introversion, shyness, etc. don’t change much. Confirmation bias can easily lead us to believe that the school choice has a major impact on personality, when it most likely doesn’t. Different personalities simply choose different schools.
What you can guarantee is that you’ll have $100,000 less if you attend Penn. That money, if invested over 40 years at 7%, will be over $1,500,000. In 20 years, over $390,000. That is the true cost of choosing Penn over GT on a pure financial basis. All other factors aside, which can be highly subjective, that’s a huge opportunity cost. That money will allow different choices later in life, all other earnings factors equal, which they are very likely to be.
What you can also guarantee is that GT will be more heavily recruited than Penn, probably by a significant margin. It is seen as a “go to” institution by lots of employers, deserved or not.
Finally, any class that is taken that is not a tech class means taking one less tech class. It is a zero sum game. I’m not saying there is no value in non-technical classes, but I do believe most employers would prefer to see advanced vibrations, advanced heat transfer, tensor calculus, numerical methods, etc. over philosophy, history, etc.