I don't think you should avoid those situations either, the thing is you need to set your expectations to what is realistically possible. A startup is a gamble,

I don't think you should avoid those situations either, the thing is you need to set your expectations to what is realistically possible. A startup is a gamble, we all know that - and you are increasing the odds against you when you are relying on some third party. It doesn't mean everyone should stop working with third parties, but it does mean that it is a sizable risk that you are adding to your business model, and you need to be aware of that when analyzing the risks you are willing to take.