The main scenario that springs to mind is to avoid the authorities, which is less about survival and more about being a criminal on the run. We've had some in the UK who evaded capture for a while.

In a pandemic, or if there were bad civil unrest, it might make sense to avoid population centres. The trouble is, many other people would have the same idea and in the UK we don't have enough wilderness to go around. I would prefer to bug-in for both scenarios.

I will say that being able to survive comfortably in the wilderness is a good thing. There may not be hotels or other civilised places to stay. Having a tent that you can pitch in any field gives you options over going to some emergency shelter. (However, even a field isn't really wilderness.)

Really? Leaving aside whether bugging out at all is an over-reaction, why bug out to the wilderness specifically? Why not go to a hotel in another town, or stay with friends?