I have plans to bug out to several locations, depending on the circumstances: my sister's home up by Auburn, a hotel in San Diego, a ranch in North County, Mexico, and Arizona.
The BOB is needed for several reasons. First, I can think now at my leisure and pack things I may need (I pack modular, so different little parcels depending on the situation) instead of trying to remember where my passport or sunscreen is when I'm under time pressure. Second, a trip that might take a few hours today could take a couple of days under some scenarios, and a trip that might take 10 hours today could take a week; I'll want more supplies than a bottle of water and a debit card for McDonalds.
While one could certainly do some fishing, I don't think it wise to plan to live off the land. Even 150 years ago American pioneers were "moving on" because game was becoming scarce; any real pressure and game will seem to just disappear. Most good hunting even today is on land that is protected or controlled by law or by the owner, and I imagine private owners will be more serious, not less, about protecting their resource in many scenarios.