"another possible scenario is working at a consulting/banking gig and paying off the $80k debt in a few years after college while being sent to a prestigious MBA program by an employer.
Depending on the “elite” college OP is talking about and its track record of sending graduates to $100k+ consulting and banking jobs the LAC route can still work to his/her advantage. "
Another scenario that is far from guaranteed. And these days, really only MBB covers the whole MBA tuition. I can guarantee you that far from everyone who wants to enter MBB from undergrad manages to do so even from the LAC with the best placement record.
Same with IB.
Not to mention that IB hours are insane and those jobs tend to be in high cost areas that make paying off debt difficult.