As much as you put a valid argument forward about the "competition catching up", there's actually no other ecosystem available to compete with Apple at present.
And thus supporting their financial performance. For now. I keep buying Apple products when needed, even though I absolutely detest anything software-related that Jony Ive's gotten his hands on since 2013, because they're still the best option of what's available. I bought my nephew a MacBook Air for college this summer, but for me personally my last purchase was an Air in the summer of 2014, I rushed to get it a little earlier than I needed because it still had Mavericks on it. Still does. I am probably in the minority, where I truly detest apple's current UI in iOS and OS X to the point of clinging to mavericks, for example, but as soon as a competitor with an equally well put together ecosystem and UI that's engaging like apple started to shine for many in the mid 2000's, just watch what starts to happen. Don't forget, consumers love to rag on something once it starts to really mature while showing a worsening of product (example: Microsoft Windows was a real darling in the early 90s but then after the mid 90s they started messing around with the operating system often with poor results and with increasing frustration and decreasing consumer happiness). Apple's current iOS and OS X hardly feel Apple-like and magical. But we know they once were, and like you say, many of us are very invested in the ecosystem. So just watch… It takes a while to turn a large ship around, but just wait and see.