All of them without exception went on missions and got married in the temple and are successful in their careers. Some of the non-BYU goers have done likewise, but a certain percentage just power through school and compromised on missions and temple marriages. BYU tends to build up testimonies and gives you lifelong friends with like minded people, which is harder to find at other schools. BYU undergrad takes you to about the same spot academically as an Ivy league school, especially if you have graduate school plans. Comparing alumni bases and bump in prestige is what it comes down to other than the experience of attending each school. Those factors usually doesn't make or break a career.