Is DEGOV a possibility?
No, it is not possible. At least not over the long term. Extremely weak governments such as what you describe will ultimately get overrun by stronger governments looking to expand. Look at what happened to the Indians in the early days of the United States.
Native Americans were centuries behind in technology and were outmatched by the settlers. The people absolutely would fight back against an attack. We don't need an organized military to do that, we just need some Americans that aren't braindead and still care about their freedom.
Decentralized governments will ultimately have a weaker military and will be less able to fend off attacks from stronger governments with a strong military. Decentralized governments also will not be able to spend as much to develop the 'latest and greatest' in terms of military equipment, so it would quickly become outmatched.
Unfortunately that is true, the only way around this issue would be if all the decentralised countries would work together. If all the countries are in the same faction and have defense alliances in place than the military aspect wouldn't be so important anymore. Eventually humans should evolve out of then need for war and start resolving our conflicts in a civilized way.
OK this is getting deep now. The purpose of any government is to deal with all of the admin side to society. Their roles are just glorified admin roles.. Their purpose is to work quietly in the background, nothing else. But what has happened is they are the naughty cashiers who started to take 50p when no one was looking, then they pumped their steals to £1... now they are just outright taking the piss.... If not all aspects, then some aspects need serious consideration in regards to decentralising, such as voting for one... As well as where your taxes go (take Texas for example, gas pipes not maintained over the years, they opted out of updating the gas pipes with winter insulation to most likely syphon off millions in off-shore accounts - to the tune of hundreds dying of no heating or water - in America in 2021?!)