Some points on the "cap unfrozen" and "cap hits are going up" points...
1. The cap is not guaranteed to go up. Economic/political/acts of god events can hamper that. A recession, pandemic, currency crisis, or political volatility might cause the "projected" cap increases to slow down significantly. Planning for the best and assuming away the worse is not shrewd.
2. Even assuming cap growth, you've kinda missed the point about salary inflation and who you want locked in at fixed costs. A growing cap means you really want to lock in star players now, not 5D and third liners. E.g., if the cap goes up 20%, a 1st line $10M player now becomes a $12M player. A $3M 5D becomes...a $3.6M player. You can pretty clearly see, in terms of absolute cap space (which is what matters for cap allocation), the cost increase is much higher for a top-of-the-lineup player. Thus, there is a much stronger incentive to pay more for high-end players now and lock in those costs, even if you end up paying depth players more down the line, because the cost savings calculation is more beneficial doing it this way.
Teams that paid a ton of money on middle-of-the-lineup players *cough Seattle cough* made colossal mistakes.
3. The cap going up is not some get-out-of-jail-free card. It's not a competitive advantage. It goes up the same for every team. Using cap space efficiently and having guys out-perform their contracts is still the formula for success. Vegas GM McCrimmon literally just said this at his July 1 presser, amid criticism he didn't pay up to retain some of his UFAs.