There is no doubt to me that they exist. So will they save us? Most likely being pragmatic, probably not. They probably feel that if we are stupid enough to destroy ourselves, we deserve our fate. Also, if they had any intention to do so, they would have acted by now. Also, there are many ancient structures around the world that couldn't have been built without help from extraterrestrials. Because even today with all our advanced machinery, we would be hard pressed to do it. If it could be done at all. One of these sites is Pumapunku. The only reason why I can think that they would do so is to leave a message to future generations that they were here. That is, without making it too obvious. Like by leaving advanced machinery around. Also, even with these extraterrestrials around, it didn't keep the cultures that built those structures from disappearing.
Even intelligence among humans doesn't seem to help. Around 20,000 years ago, humans had brains that were larger by about the size of a tennis ball. It is also quite possible that there was an extinct species of human called Biscop man. It had a brain much larger than ours. No doubt increased intelligence must have come with it. But they too died out. It seems to me that the major problem is human desires and biological drives taking precedent over doing what is right. To survive, this a keyhole that the extraterrestrials must have had to pass through in order to survive. And advance.
So, for us humans, you may wonder what it is that we must do in order to survive ourselves. Well, just think of whatever you think should be done. The answer almost certainly be the opposite of what you think it is.