None of these things are true at Google, Facebook or half the other places on OP's list. These companies will not fire you at will. You will go through at least

None of these things are true at Google, Facebook or half the other places on OP's list. These companies will not fire you at will. You will go through at least 2 cycles of poor reviews and a performance improvement plan, it should be obvious at least a year out that you're not cutting it. All of those companies have great benefits and generous holiday time. Some people have an oncall rotation, but they know what it is ahead of time. Others don't.