Would they? Microsoft also own other stuff they monetize like GitHub, Linkedin, X-Box, and a shit tonne of gaming IP inclusing Activision Blizzard, plus other things I'm surely forgetting.
Looks pretty diverse to me comapred to a company who's revenue stream is limited by the ammounts of walled garden phones it can sell and who's grasp over its walled garden can be regualted away by the EU waving their wand the same way they lost the Lightnig cable revenue stream.
Can Apple keep up this momentum in the long run and keep growing by getting people to buy more expensive stuff, or will they slowly loose steam and stagnate?
Office and Azure make up half of their revenue, but their other revenue streams are actually different things, like Windows, gaming, LinkedIn, Bing advertising. It's actual diversification.
With the introduction of IE in 1995 and its deep integration into Win95 and ruthless take-no-prisoners assault on Netscape, Microsoft was probably already aware that they were starting to resemble a monopoly, given Apple's poor sales and market share at the time. My personal take is that MS propped up Apple to help appear to have a competitor ahead of the Antitrust action in 2001[2].
[1]https://www.cnbc.com/2017/08/29/steve-jobs-and-bill-gates-wh...
[2]https://en.wikipedia.org/wiki/United_States_v._Microsoft_Cor....
I'm _pretty_ sure Apple could have gotten the money from elsewhere if they really had to. It's history now, so we'll never know for sure, but I'd bet that they could have found other investors if they really had to. People seem to think it's a black and white scenario - money from MS or death! But I don't think it ever was.
They were already on a bit of a shaky nail for a while when they relied only on Office and Windows, but their shift to the cloud (and resultant cuddly Embrace of Linux) has paid off well for them, so overall a smart move on their part.
One way to think about this is that Apple isn't diversified enough. Another way to think about it is that Microsoft's long tail is a mess.