So my problem whenever people say “wait until next year to grab a QB”, is that it doesn’t make any sense. Too much uncertainty. Who are we waiting for? Trevor Lawrence? In all likelihood he’ll be the 1st overall pick. Justin Fields? Likely goes somewhere in the top 5. Unless you want the Colts to tank (which they never would) then it doesn’t make sense for them to wait for QBs they might not get next year.
If all you're going to do is to build through the draft, it will take longer than 3 years. It might be able to be done with a Luck who can carry a mediocre roster by himself, as long as he still wants to do that, but to get a championship roster it takes longer than 3 years regardless of the QB, IMO.
A GM has to hit on every 1st and 2nd rounder, (six premier players) and get lucky with a few mid to late rounders that play way better than expected. That hasn't happened so far.