Half of developers in North America, and especially those at top tier companies, use Macs. You can't buy that kind of top tech mindshare with marketing. Also now with the M-series CPUs, Macbooks aren't PC Clones anymore, they're back in the game of being an exclusive platform, which will get even more exclusive as they add other specialized chips. Their sales share of the market and as you mention, their profit share of the market keeps increasing, so even on that alone, why would a bean counter decide to drop them?

Don't forget Apple's size... the AirPod business, stood alone, would be a Fortune 500 company. Even if an Apple business is a bit small compared to the iPhone, it's still a humongous business by any other comparator.

I'm not an Apple fanboy (e.g. I use an old Chinese Android phone) but I'm still awed by their business.