Yeah, maybe it's gonna be ugly for a few years while the UK recovers its independence, but eventually they will essentially go back to functioning just like 90% of the countries on earth. In the mean time, with the situation in Greece, Italy, Eastern Europe getting pretty nasty, who knows what's gonna happen in the EU in the next 5 to 10 years?
I think it is naive to assume that in the current political climate with huge actors (US/China/Russia/India) and the potential for trade wars that the UK will come out better from this especially with their previous privileged position.
There are plenty of countries way smaller than the UK that do just fine on their own, and don't feel the need to merge with their neighbors. There are pros and cons to forming alliances with other nations, but 1) they don't need to be as involved and permanent as the EU, 2) they don't need to be primarily based on geography.
e.g. https://medium.com/@gordonguthrie/no-deal-wont-happen-e185f9...
Realistically the options are "disaster Brexit" (fail to make other trade arrangements, lose NI and Gibraltar, huge airline losses, shutdown of nuclear reactors run by EDF, etc) or "pointless Brexit" (everything remains roughly the same, except the UK loses its vote)