Turns out the Jaylen Brunson "pay cut" isn't exactly a pay cut. He can opt out of the 3rd year and get a new contract with the 10-yr vet kicker, and recoup all the $ then. It's a bit of a gamble, because maybe they won't max him, but the likely scenario is he gets the same amount of $ in the long run and they have more cap flexibility. over the next 3 years.
And in a way, it also gives him some security, because signing the extension now (instead of waiting a year and getting more) gives him 3 more years of guaranteed pay (in case something catastrophic happens this year).
The reason the Brunson extension can't be more right now is because of his current salary and rules about FA signings. In other words, the NYK saved twice by signing Brunson for substantially less than what his value is, and consider they slightly overpaid him vs. his market value.