Graduating in 4 years vs graduating in 6 years
From the point of view of a graduate admissions committee*, the undergraduate degree is just one step in the sequence:


elementary school
middle school
high school
undergraduate
graduate
postdoc
tenure-track
associate prof.
prof.
named professorship
chair, dean, provost, chancellor, ...


*although they'll realize that many applicants will want to stop going down this list after the graduate degree.

It's okay to take extra time in any of these, but it does delay moving on to the next one.