Well, if I were in charge of Apple, I'd be a bit worried although everything looks so fine.
When I started in the Apple/Mac-business 20 years ago you got laughed at for buying Macs or anything Apple. It was expensive, seriously lagging behind everything else and frankly, of very low quality.
Then Jobs and the i-revolution came and Apple rose to become the famous trademark it is today.
10 years ago, I still had to fight to keep Apple at my workplace, although the switch to Intel made it easier to be allowed to buy Apple, if nothing else, they could run Windows and looked better than the PCs.
Now, everyone wants macs on their desktop or in their bag, and of course an iPhone, but in the shadows lurk the money. In the last 2 years the complaining about the prices have risen. We are forced to buy MBAs to be able to afford macs and just the other day, I got word that the main IT-dept (I work at a uni) has stopped replacing macs every 3 years and aim to keep them for at least 4 years, to save on costs.
Today I had lunch with our Apple distributor and the sale of iPhone 8 is a lot slower than previous releases. People opt for older, cheaper versions still on sale or keep their phone for another year.
The competition is catching up, the HPs we buy cost half of a MBP and frankly, look quite OK compared to the plastic crap of yesteryears. My Huawei P10 is performing admirably and cost only a third of a new iPhone 8.
Apple could price themselves out of the market in the future as people no longer see the benefit of pouring out large sums for stuff not that much better than the competition.
There will always be the "fanatics" that'll buy anything to any price, but the "masses" often make a more sensible choice. So far, the iPhone has always been expensive but not as expensive it is today. I guess the iPhone 8s slow sales could very well be partly due to the prices, and the iPhone X is not cheaper.
On the mac side, the only really "affordable" computer is the MBA which by now is a 7 year old design with at least 3 years old tech inside.
If I look around at the uni, I see a lot more Android phones and PCs than I did 3 years ago, it's actually noticeable.
When I go to the US, I see a lot more Apple stuff than I do here, and I don't think that's due to us being "poor".
If Apple fail to penetrate new markets like China and India, the sales may very well slow down. Not like they're going anywhere soon, but if the spiral turns downwards it might be difficult to turn it around once more.