You summed up the pros and cons of art school excellently, in my opinion. Back when I was an art student, many years ago now, options like RU-vid hadn't even been dreamed of yet, and a person can now learn as much from browsing videos here as they can from listening to tutors in a traditional classroom environment. One thing which so many people tend to skip over, though, is that the best way to improve as an artist is to draw from life, and to practice. Nothing can replace prolonged practice.
There are many different ways to learn... getting a BFA or MFA... is just about the worst investment of time and money if one wants to become a successful artist... in my humble opinion.
I have learned an incredible amount from art books and magazines and from a few fabulous instructors and I have a diploma in graphic design but I did not study “Fine Art” at a university or college.