I'd argue that those guys are worth more like $50 million, the other star level players are actually worth the max, at least the 30% one, if not the 35%, and some even more themselves, but it's the average players who are getting overpaid and taking up more cap space than they should. My 8th man making $8-10 million is not the guy bringing me revenue or driving my wins.
Either way, even if there are just 4-5 players worth the max, there are 30 teams in the league, and even then, two of those players are on the same team. If a franchises plan is only to ever pay the max if they can get one of those 4 or 5 players, well then, good luck because that's just not how the market works. The other 26 teams will gladly do so and you'll never sign anyone significant.
Even the third tier stars, the Blake Griffin's and Kyle Lowry's can't be had at any significant amount less than the 30% max. Boston gave Hayward 30% of the cap. So you couldn't even build for example a team like the 03-04 Pistons without shelling out max contacts. All those main starters would be anywhere from 25-30% of the cap, assuming no special circumstances or bargain situations, just getting the same level of talent now.
The nice value though is the 25% max after rookie contracts and young productive players before their extensions. The problem is that the guys getting those are restricted FA's, so busting into that market is not really realistic unless it is your player or unless you trade for them later and want in the contract because they are disgruntled (Kyrie's current contact for example). You have to try and work the timings of your players extensions and the contracts you are signing to maximize everything. You can't always do it, but you have to try.