It isn't a zero-sum thing, and different people go to university for different reasons.

For me, minimising the debt at the far end was important, so I took a heavy course load and worked half time on average. Work experience from that period (IT for the university) was actually quite valuable in the jobs (mainly engineering) I've had in the decade since. Maybe one employer has ever even looked at my school paperwork; I really don't understand the idea of doing nothing but university with that time.