It seems a counterproductive direction given the recent years explosion of startups and e.g. app development.
People and their pain are very different in general, but rather similar in specific groups. Almost everyone spends almost all of their time in a bubble that excludes the pain points of most of the world. And, for someone with the skills, possibility and desire to run a startup, it's exceedingly likely that your market is oversaturated already.
Pick any demographic metric.
For age, the personal pain points of 15-30 people have an overabundance of solutions, but the pain points associated with 53 year olds or 9 year old kids have more gaps and possibly even more paying power.
For lifestyle, the pain points of single young adults are oversaturated while needs of large families (possibly excluding baby-apps) are not, again, due to the peculiarities of startup employee demographics.
For types of location, even the minor pain (inconvenience?) points of people living in highly dense urban areas have all kinds of startup solutions, while pain points specific to millions of people living in USA rural areas are pretty much ignored.
For social groups, the subcultures popular in Silicon Valley have their specific needs filled much more than the various minorities and cultures which are mostly elsewhere. Pardon me for a crude example, but for example, there is a competitive market in gay dating apps/services with a lot of solutions developed; however, the USA LGBT population is comparable in size and thus purchasing power to the Mormon population - if you're starting a new service, which market has the larger potential for you to serve a need that's not already served by existing solutions?
For technological aptitude, the needs of early adopters are obviously served by new tech, while you definitely can build solid businesses designed to serve the far more numerous people who want to avoid bleeding edge tech or even don't have the skills or desire to use industry-standard tech - if they still have the same needs, then making that tech more friendly to them or more distant from them (having you do stuff for them by that tech, instead of having them interact directly in detail) will bring you good revenue.
