Apple is a key member of PRISM [1] and got on board just about the time their phone business started to skyrocket. Just because the media stopped talking about PRISM doesn't mean it went away. If anything I'd expect it's only grown more emboldened given the relatively tepid public response to it. I'd argue this is likely the real reason that Huawei was banned. The US 3-letter agencies agencies had the choice of bringing a Chinese company into the surveillance state web, having a phone on the market they have no control over, or simply banning those phones.

As for incentive, big tech regularly flaunts nearly every single behavior that all of our anti-competitive clauses were meant to prohibit. 'Back in the day' Microsoft was targeted, and lost, an anticompete lawsuit for bundling Internet Explorer with Windows. Now a days bundling everything in your own packages, locking down other companies into a an unescapable market where you impose a 30% tribute, buying out competitors to prevent competition, and more - that's all perfectly cool, somehow.

If Apple, Microsoft, Google, et al stopped playing ball - they'd be out of the game before nightfall.

[1] - https://en.wikipedia.org/wiki/PRISM