I feel like you are taking everything I am saying to the extreme...
The point is that you never know until you need them and they either fail you or not, and even someone that has been there for you everytime for years and you might consider to be 100% reliable, can surprise you and stop being reliable.
It is a fact that no matter your situation, you are not guaranteed to have external support, but obviously for some people it is extremely unlikely to happen and for others it is more likely.
Thank you