I see a lot of cases of major 'fixer upper' homes or general home improvement done in an area where the Authority Having Jurisdiction (AHJ) requires permits and only offers them to licensed pros. How is this the case? I ask because I wonder if I'm missing something. (Of course it is case by case. For example, one person doing electrical may be working with a licensed electrician to do so, whereas another may be outright doing it themselves illegally. Same goes for structural modifications and remodeling.)
From what I can tell, many people are doing work that requires a permit & license without either. Aside from doing unsafe work, what risks are they taking in doing so? I'd think the risks would be high but the prevalence of this suggests it is not. Part of that could also be, many of the people illegally doing maintenance/upgrades are trying to save a buck, or are doing it on homes that are in such bad shape to begin with that their DIY improvements can only bring good things in quality of life and resale value there.
For more context, consider the answers to Does a homeowner need a permit for electrical work in Massachusetts? It is clear that in some places permits & licenses are required for relatively simple work, and also clear that there are people who don't respect those requirements and would rather risk paying a fine than a pro.
And in another related question, Pros and Cons of buildings permits the risks are made clear, along with reasoning why someone would ignore permit requirements.