Why are micronations founded?
It takes only a single individual to accomplish simple tasks. You don't need a micronation to instal a door knob, although a friend or neighbour may be helpful. You also don't need a micronation in order to start a family. A loving and agreeable spouse is all you need in this case. In many cases a family is all you need to start a business as well, although this is becoming less and less realistic with the growing complexity of today's products and services, and with the growing competition of national and global markets.
Most micronations are founded by minors as political, more than socio-economic simulation, but these micronations usually don't last long enough to deserve to be called micronations.
Some micronations also start as personal entertainment or self-aggrandisement. Here the founder is usually someone with extra time and money, and with a humongous ego. While some of these can live for decades, since the foundations are not in a shared or national experience, these micronations never become compelling enough to ensure the longevity of the entity beyond a single person's lifetime.
The micronations with the greatest probabilities of success, however, are those which are vehicles for the promotion of an agenda, micronations which are historical anomalies and aspirant states, and new-country projects. These are usually started by older adults, and the motivations here are often less egotistical or purely political.
It is hard to predict which micronation is most likely to succeed in the long term, but definitely the micronation which is the most shared and happy experience is the one most likely to succeed.