Look at any relativity free market. Are you overwhelmed by incompatibilities? Most video connections are HDMI these days. Most gadgets take AA or AAA batteries. Most cell phones use mini USB to chargel. Most cameras use SD memory cards. Most cars have CD players. I could go on and on. There aren't government regulations that force any of this to happen. Businesses want to make money and while there is money to be made in variety, that only goes so far and only when it makes sense. If people want standardized laws, they will get it. If people want different laws but to be able to know when those laws apply, they will get that too. Someone could make a GPS device that detects your location and shows the laws that apply in that area depending on which court system you subscribe to or whatever. Don't underestimate how smart people can be when they are acting out of their own selfish interest to obtain wealth.
Don't underestimate how lazy and how nasty people can be, either. I've experienced enough spontaneously developing cultures in online games to know that mega-collaborations with shared "laws" are an almost inevitable result of anarchy.
The difference is, nasty, lazy people in real life get other people killed, hurt, or imprisoned. There's a huge difference between various interpretations of "human rights" and the size of battery you put in your latest dongle. The benefit of founding principles and a centralized system is consistency and reliability. Unless AnCap or p2pgov can meet or exceed that benefit, it will never work.