If you don't have someplace to go, you've failed to plan.

Before you start looking at the sexy toys, the first, nay, the ZEROTH thing you have to do once you made the decision to develope a bug out plan is have a destination, a "bug out location" (BOL). Preferably, people are normally at your BOL and the expect you rather than repel boarders as soon as they see you.

Then, and only then do starting assembling your kit with the time it will take you to get there in mind. Assume you'll have to walk. For some people, it is under 20 miles, say a family member or a friend who lives on high ground and has a solid house. Or 20 miles to get from work to home. You can generally push that through in a day, without significant stops. It might mean an all nighter on your feet, but it works. I don't have that luxury, even if my primary route has a couple of way points where I might be able to beg some floor space (or a couch to crash on during a short term disruption) it is 70 miles to my primary BOL, so I plan on spending every night in the field until I get to where I'm going.

BOB is a survival machine, just like an life raft or an ejector seat. It doesn't have to work for everyone under all conditions, just you under your conditions. It has to be able to get you to your BOL(s) under your own power. Sometimes, you'll have transport and you won't need BOB's contents for very long. Other times, you'll have BOB and a pair of shoes and maybe your glasses or underware (pick one). Either way, BOB must be able to give you what you need accomplish your objective given expected duration (plus a safety margin), your local conditions and your personal skills. But if you don't have a plan before you pull the pin, you are at best going to be a well equipped refugee. At worst, you'll be a well equipped corpse, at least until someone finds you and picks your pockets.