I find this completely unsurprising. Maybe because I'm someone who used to (kinda sorta) make a living as a writer?
Writing software is more profitable than writing prose (or poetry), because fewer people can do it, but at the end of the day the economics are the same: the fruits of your labor are easily copied, so making something that 10 million people read or use is not inherently much more expensive than making something 100 people read or use. Under those circumstances, it's easy for everyone to read the best content, and use only the best apps. People's differing tastes, need for variety, and imperfect awareness of their choices means the authors of the "second best" thing aren't completely screwed in either case, but it's still pretty close to winner-take-all.
(Also, social proof—people's tendency to use what other people are doing as a proxy for quality—amplifies winner-take-all tendencies, even when there are no obvious network effects.)
Writing software is more profitable than writing prose (or poetry), because fewer people can do it, but at the end of the day the economics are the same: the fruits of your labor are easily copied, so making something that 10 million people read or use is not inherently much more expensive than making something 100 people read or use. Under those circumstances, it's easy for everyone to read the best content, and use only the best apps. People's differing tastes, need for variety, and imperfect awareness of their choices means the authors of the "second best" thing aren't completely screwed in either case, but it's still pretty close to winner-take-all.
(Also, social proof—people's tendency to use what other people are doing as a proxy for quality—amplifies winner-take-all tendencies, even when there are no obvious network effects.)