Most available data gives Apple a 3-year failure rate between 15% and 17%, which is fairly in line with other top quality vendors like Asus and Toshiba - not as amazing as you might think?
3 Year Laptop Malfunction Rates By Manufacturer Anecdotal data would have you believe that an Apple laptop has a very low failure rate... after all, how many people do you know who have had MacBook failures? But remember the market share effect. In any given quarter Apple may ship as much as 9% of the new laptops manufactured. If Apple products fail at similar rate to everyone else then you are 10 times more likely to encounter a PC user with a failed laptop than an Apple user.
Apple products are every bit as susceptible to defects and product flaws as any other OEM: Widespread 2011 MacBook Pro failures finally get an official Apple repair programme (This one took a class action lawsuit before Apple modified their warranty program to address the high failure rate of Apple MacBooks with a certain GPU.)
We fix a lot of MacBooks. Every week we repair between 3-8 MacBooks and MacBook Pros. They have a variety of issues - the most common being hard drive failure.
The truth about Apple products is that they fail about as often as several other competitor products. In general, the safe business life cycle for laptop replacement is about 3 years. As a consumer, you may be able to budget 4 years for a laptop. Of course, outliers will exist and there are plenty of anecdotes about Apple quality. But if I can co-opt someone else's phrase: "The plural of Anecdote isn't Data."