I wouldn't trust an engineering graduate who scored 100% on all their exams to design a bridge at all. Where as someone with 10+yrs relevant experience but who got 60-70% in their exams would be preferable to me.

Mastery of the math isn't that relevant due to all the design standards you have to understand and comply with anyway, while all the little pragmatic solutions to real world constraints (incl how the builders work and what they need to be effective) learnt from experience and mentoring from your senior peers are far more important.