Fangraphs crowdsourced estimates are far from gospel about true market value, but they are at least a consistently applied estimate. Of their Top 25 estimated contracts in total value, 22 of those players have signed, the 3 remaining unsigned are Snell, Montgomery, and Clevinger. Of those 22, the only ones who did not exceed the estimate in AAV, total value, or (in most cases) both are Kershaw, Stroman, Soler, Chapman, and Bellinger. So setting aside the obvious cases where there are external factors(Clevinger being a pariah, Kershaw's injury and Dodger history), you have 6 players who are underperforming contract expectations, with 4 of them being Boras clients. So this is either extremely targeted collusion, or Boras had a beyond the pale valuation on his big clients, decided to wait out for desperation to set in, and other GMs decided they couldn't wait and largely spent their money(of which there were fewer surprise players because of the Bally implosion) elsewhere.