There is no shortage of ideas for startups out there and you can look to any sector and see tons of opportunity for efficiency (especially when you are still using manual workflows vs. any sort of automation). This focus on efficiency could blind one from seeing the larger opportunity ahead.
A great example here is Uber. At first glance, you could think of Uber as a more efficient taxi operator, and you could look at the taxi space and say that it is not that large. But after seeing Uber play out – what has happened is that it has enabled anyone to become a driver, thus increasing supply, thus allowing for the entire industry to expand and allowing for a ton of value creation…. and the rest, as they say, is history.