Apple is living proof. Some large chunks of the iPhone are actually done by half a dozen engineers. When I was a PM at Microsoft, our whole team was something like 40 people on data synchronization.
Final Cut Pro was around 15, which is still incredibly small given how big our application was.
Then take into account all the people who do QA, all the management, marketing, business, finance, and other teams.
And you're actually left with a pretty lean engineering force. Apple engineers more stuff in house than a typical company like Dell, so that plays into the head count as well
Apple lets go of a number of things that Microsoft chases such as a religious concern for backwards compatibility, globalized features (not just localization but geo-specific features), and deep product extensibility with corresponding dev support. No judgment on those decisions but I'd argue that the size of MS teams isn't directly reflected in the product or features most folks consider as users of Microsoft's products and I wouldn't criticize MS based on those team sizes (as the author of this article does). Instead, I'd criticize the PMs or other managers inability to bring focus to those teams to clearly tackle the right problems at the right level of investment at the right time. It takes a lot of discipline to say "no."