Impression share lost to budget or lost to rank - which do you actually chase?

Perennial argument and I would like to hear where people land. Lost to budget says you ran out of money. Lost to rank says you were in the auction and not good enough. Every rep treats both as a reason to spend more, which is convenient for them and not always wrong. My position, arrived at over too many years: lost to budget is only worth fixing if the traffic you are missing resembles the traffic you're getting, and on a capped campaign it frequently doesn't - you're missing the end of the day, which in most businesses isn't the same customer as lunchtime. Lost to rank is worth understanding and usually not worth buying your way out of, because the reason you lost is often quality rather than bid... The counter-argument I have never fully answered is that at 40 percent lost to budget you have no idea what you're missing, so the reasoning above is speculation dressed as judgement. Where does everyone else land on this? Particularly interested in anyone who has actually lifted a budget substantially and measured what arrived rather than assuming it was more of the same.