Right - you said it better than I did. The UFA game is tilted against the Spurs b/c of the media market and other endorsement opportunities available in bigger markets. Even if we max cap space, if it's a choice between Brooklyn/NYK/LAL/LAC/Miami/Chicago or the Spurs...we lose, and end up holding the bag like we did w/ fucking Morris. All the evidence from the past decades shows this - we don't get good FA's. We get back-half-of-his-career LMA, Malik Rose, and Michael Finley. Now one could argue that we haven't had to compete for FA's at the highest level because we had the core in place, and that's fair. But looking @ all the small market teams in the NBA, it's a pretty clear trend. You might get a single diamond who grows into an all star, but it seems like the trend now is that the biggest star FAs have figured out the power they hold and are looking to move in pairs or triplets. We've never shown the ability to pull that off - no small market has (Cleveland, maybe? If you count Kevin Love?).
What we have shown is the ability to execute the Spurs system and grow talent within it - at least for the bench players and solid one-step-below-All-Star rotational talent. We have N=1 datapoint of growing talent to All-Star level in Kawhi, I think it's fair to say Pop and team developed him and raised his ceiling far beyond what was foreseen when we was drafted, whereas Duncan was always going to be All-Star talent and I'd argue the same for Manu and Tony. So we know we can grow up the peripheral players, the question is how do we find the core 2-3 top players. Trade, FA, or Draft?
Trade - first we don't have anything worth trading. Our top assets are either at the end of their careers (LMA), not a good fit for the modern NBA style (DD), or too early in their career or we can exploit too much potential that we wouldn't get appropriate value back (DeJonte, White, maybe Lonnie). I see this as zero sum in terms of assets received back, unless we consider it addition by subtraction and are able to dump DD/LMA to free space for...
FA - this is a bad place for the Spurs based on above discussion. At least for the top tier superstars. The issue is if we get impatient we might land ONE...but not the 2.5 we actually need to compete in the West. One superstar like a Giannis is enough to put us in NBA purgatory like where the Bucks are about to be: exit the playoffs early, with shit draft position, repeat. The other place for FA is to build around the superstar, but the issue here is that you don't want to get complimentary pieces in the FA market until you have your stars in place because otherwise you bring in the wrong stuff and overspend. Better to hold chips here IMO.
Draft - we have demonstrated success here at all levels. We just need to get high enough in the draft to get that next star on the cheap first contract. Once we have that, you can make a legit play for additional FA or trade pieces to pair them up and our superior development and system can take over.
tl;dr - what you said, but with more words