Let's say lowering the bar has the result of making two courses absolutely useless for you, because you've already mastered everything there is to know about them. And let's say your typical bachelor's degree includes 30 or more courses. The time "taken away" from you is around 5%. Time that surely you could spend by studying for the other courses a little bit more diligently, by solving all the optional homework exercises, by going the extra mile for projects.
That said, if after your undergraduate degree you are unsatisfied by the amount of stuff you've learned thus far, there's an easy solution: continue on and pursue a master's degree.
That said, if after your undergraduate degree you are unsatisfied by the amount of stuff you've learned thus far, there's an easy solution: continue on and pursue a master's degree.