You're also assuming that (a) the cap will go up every year - a reasonable assumption, barring another pandemic and (b) the amount you are kicking down the road stays generally proportional to the cap increase. That's a lot harder to predict and manage, especially since teams don't know the cap increase until just before the new season starts. If the cap goes up 15M but you have to eat 40M because of Bakhtiari and Jones and Rasul, you've kicked too much.
Was going to make an analogy with the national debt and growing economy/GDP, but that wades into FYI so I'll skip it. Point is, red is somewhat correct but managing that ratio of can-kicking to cap increase is almost impossible.