The question for me is how many potentially-good QBs were destroyed by poor OL play. Yes, it's important to get the QB, but you also have to make something of him. For all I know Chad Kelly with all day in the pocket is better than Josh Rosen under duress on every snap. It's a rare QB who is better under pressure, especially a young one.
Whether the Broncos take a QB at 5 or not they have to fix the line. Whether they can actually find OL fixes later in the draft or in FA is a big deal, because they've had poor luck so far on both counts.