Failure due to not enough critical mass
For some thing to be successful, it needs critical mass. If a company doesn't get enough customers, it shall shut down. Same with websites and blogs, if they don't get visitors the creators or author loses interest or loses money for long enough they stop.
How do we derisk endeavours? How do you guarantee critical mass? To me this seems the most important issue for effecting change of the 21st century as it defines the nature of success
If you ask people what they want they shall tell you what they want but they might not pay for it. So you cannot rely on market research completely to get customers or users.
You need to pivot repeatedly to what the market requires.
Society seems to have settled on advertising as the key to getting people to use something and it's not the greatest use of technology.