Tea is extremely important in a survival situation. Coffee is not.
In a highly stressful survival situation the brain of the individual may become confused and disorientated and panic may ensue. This will lead to the individual making the wrong decision, which will lead to a situation whereby the survival event is even more difficult to deal with. This will then lead to even more poor decision making with the consequent loss of life of the that individual. Survival ultimately is about making the correct decisions.
In the US army, soldiers are taught not to stop but to continue to be proactive, the assumption being that mistakes can be rectified and survival is assured. The assumption is that inactivity leads to a loss of moral and consequently gives rise to a sense apathy and defeat. This is the supposed flight or fight response to stressful stimuli. US army soldiers drink Coffee. Apparently caffeine is even put in that awful chewing gum stuff which makes you average GI even more hyper. This of course has its downside because I have even read that additives which cause constipation have been added to their MREs. The reasoning behind this I suppose is that it stops inappropriate bowl movements in highly stressful survival situation.
In the British Army the opposite applies but they have a secret weapon call the brew kit. In a highly stressful life threatening situation, the British soldier will sit down and make a nice cup of hot strong sweet tea if time allows and if the threat is not immediate. The act of making a nice cup of tea will allow the individual time enough to assess the situation and make the correct decisions and planning and allow the feelings of panic and stress to dissipate. Consequently this generally leads to a more successful outcome although too much tea drinking leads to a problem called swanning about as demonstrated at Youtube