Kraft or BB being "cheap" has absolutely nothing to do with salary cap. Teams can't outspend each other to succeed like the Yankees, this is the entire reason for a hard salary cap. It keeps player's salaries sane, and promotes parity as big market teams can't simply outspend small market teams. "Cheap" has nothing to do with it.
A lot of people lauded the Rams for spending through the nose and winning one ring, holding that up as a great example of modern team building and pretending the Patriot way has gone the way of the dodo. Nonsense... why? Because for every Ram's example there are a dozen other teams who spend through the nose and fail... yet nobody wants to talk about those teams. In short, throwing money at a problem doesn't ensure you'll fix the problem, very often you're only throwing good money on top of bad.
The Rams example is laughable anyway... the biggest reason they haven't made a first round pick since 2016 isn't because GM Les Snead doesn't value first round picks, it was to fix dumb mistakes like extending a RB with bum knees in Todd Gurley and making the desperate move of giving Jared Goff a massive contract, then having to pay a ransom in picks to get rid of those contracts. McVay is one of the best coaches and talent developers in the NFL, without him Snead would have been fired years ago. They spent a ton of their future cap to win one ring, they gave away all their draft picks like candy... now they're having a fire sale with all their best players after winning 5 games and they'll flounder in mediocrity again.
Give me the steady opportunity to be a contender that the Patriots way of fiscal responsibility provides over the peaks and valleys that most loser teams employ. Going all in at the end of Brady's run was smart, they had a Super Bowl winning roster and a chance at multiple rings because Tom was willing to take less. The team matched that commitment in borrowing from future cap, then they had to pay that bill in 2020 and have been rebuilding since... but playing in 4 Super Bowls and winning 3 was well worth it. It was certainly better than winning one and being worse off like the Rams are, at least BB never gave away his draft picks which allowed for a quick turnaround.
Draft well, spread the wealth across the 53 man roster, build from the trenches out, don't overpay and you can contend every year once you have your foundational players in place.