Barring illness, lack of funds or switching majors your junior year…Back in the day it was not all that hard to graduate in 4 years from my public state u. I actually graduated in under 4 years. 3.75 to be exact and that was with a failed class or two and a quarter of study abroad that did not count toward graduation. I made up failed classes over the summer at universities close to my home and double upped classes my senior year to make up for the study abroad that did not transfer. I knew my parents were only paying for 4 years. I had to pay for the summer school classes out of my own pocket, so basically I worked 2 summers to pay for my failing economics and math classes. It is amazing how much kids will buckle down and get it done if it is on their own dime.
I think not graduating in 4 years or 4.5 if you don’t have extenuating circumstances is on the shoulders of the student more than the fault of the university. It can be done in 4 even if you fail classes, change majors or take a break.