Let me help you decide
When God first led me to prepping I had never even heard of a 72 hour emergency kit. In fact, on my first trip to the store to stock up on food my daughter and I picked up close to a month's worth of food. God had given me (and my daughter) a "knowing" that something was coming and I would need LOTS of food in storage!
It was only after I started prepping that I heard of a 72 hour emergency kit. Don't get me wrong...72 hour emergency kits do have their purpose! For starters, they are excellent to have on hand in the case of a short term emergency such as: flooding, fire, tornado, hurricane, earthquake, or any other short term emergency. In fact, I think everyone should have one! The easiest way to begin prepping is to put together a 72 hour emergency kit. But, should a person stop there? Is that going to be enough? Well, it depends.
Lately, I've noticed that several prepper (and even survival) websites and Facebook groups are mainly focusing on the 72 hour emergency kit. Leading many to believe that this is all they will need for emergency preparedness. Ever. Our government agencies are really working hard to get this info out to the citizens as well; which is a good thing. However, last year (2018) there was a government report, Electromagnetic Defense Task Force 2018 Report, stating that there was a possibility that the electrical grid would go down across the nation and the citizens should be prepared for at least for six months or longer to be without power. The only result on the government's side that I've seen as a result of said report is the ramping up of emergency preparedness notifications and suggestions. Still only emphasizing the 72 hour emergency kit. No mention of needing to be ready for a longer amount of time.
If you truly believe that all you are ever going to need is a 72 hour emergency kit, and that kit will tide you over until government aid (FEMA) can kick in then yes, stop there. However, before you make that decision you should probably look into how effective the government's emergency aid has been in the last couple of decades. Take for example what happened after the devastating hurricane Katrina hit Louisiana in 2005. The levee broke i