I'll take this opportunity to tell a long-winded story about how that number can be two orders of magnitude larger, and still be too small.
I was with Slide when Google bought us in 2010. They bungled the acquisition (bought us to work on Google+, which had already made a bunch of disagreeable decisions by the time we were ready to rumble), so we were left to our own devices for a year, in which time about 12 of us made something called Photovine, a photo sharing app that would have competed with Instagram, and we were getting pretty universally positive press. I think TechCrunch called it the best mobile app google had ever produced, and all of our beta and early release engagement numbers were bananas.
(We also had loads of fun with it — the core sharing mechanic was organized around shared captions that we called vines, and we spent most of our play-testing time swapping visual puns.)
Anyway, if you project our trajectory generously, which didn't seem out of the question given our early traction, we would have wound up competing with Insta, doing business in the hundreds of millions. But Larry, in all his "more wood behind fewer arrows" wisdom, decided to axe the project, as he did many, many others, and re-assign all of us to YouTube, which, granted, was gearing up to compete with TV, and needed more staff.
And often, $1M/yr is not even needed. Many developers don't necessarily want to become managers and worry about funding rounds, hiring, etc. $1M/yr is already a pretty good lifestyle, no need to get further funding or scale the business if you're happy running the project on your own.
Competition isn't bad - that just means there's a market large enough for different companies to want to fight for a share of.
As a small businessperson, I find it's critical to be aware of the different strengths and weaknesses that come with being big or small, and to leverage them to your advantage.
My favorite one-liner about the difference is: small companies make it possible, big companies make it cheap.
Then you would start a marketing company. Or it will become a fight about who spends the most on marketing, and the only winner would be the marketing companies.
However, that same $1M/yr is enough to sustain a bootstrapped business and even possibly build the credibility to raise a larger round and try to win the space.
If a company is already solving a problem, a better question to ask is "why didn't I know they exist?" It may be that they aren't properly tailoring their marketing to the target audience, in which case you have a clear opening.
As a "personal anecdote", we (https://sheetjs.com/) offer a variety of solutions for problems involving structured data. Before we started, there were plenty of solutions but every solution had various compatibility issues or didn't work with our data. Even in 2019 companies turn to us because of compatibility issues with Google Sheets or Excel 2019. We went through the same analysis and concluded that neither company thinks there will be a meaningful improvement in revenue or marketshare