However, I often wonder if people aren't underestimating the effects of good marketing and sales on the outcome of ideas rather than just the market fit. Granted, a product with great market fit will better sell itself than one without excellent market fit. I often think ideas that should have succeeded and didn't, failed because of poor marketing and sales process, not because of the idea or its implementation. I think we all know of products which keep selling despite there being better alternatives.
Then actually taking the trouble to prototype it, show it to people, and find out if it has lasting value to any group of people you care about. And then you have to improve it to better fit those peoples' needs, and marketing it instead of taking a "okay, now come and get it" attitude.
Each of those steps is a huge obstacle which most people won't even attempt.
We see the finished product and think "who knew we needed that." But it's exceptionally rare to jump straight from a golden idea to a finished product. That's a marketing narrative after the fact.
Even "finding an idea" is fairly rare, and its going to waste a lot of your time if you expect it to be the first step to building a business. Find an audience, learn about them, figure out what their goals are and what choke points are keeping them from attaining them.
Then help them.
In our case we have followed the path of identifying features/ enhancements/different approach to doing things in existing products that we are using ourselves. We looked at stuff that we use in our personal life as well as products/processes that we used or developed in the professional life. This really gave us a lot of options. From these, our final selection was based on a. Our conviction that this would work b. size of the opportunity c. we would have fun working on it