Near future doesn't last long, because it quickly becomes the present and the past. A book set 20 years in the future will likely only remain plausible for a ha

Near future doesn't last long, because it quickly becomes the present and the past. A book set 20 years in the future will likely only remain plausible for a handful of years, at which point the idea of everyone having a flying car looks silly, or someone invents the mobile telephone and your plot no longer holds together.