Nope I'm not "projecting a conclusion" I'm extrapolating a definitive trend.
As to your assertion re: "consciousness (at least the human 'flavor' of it) has never happened before on this planet." Well.........so what if that's true, so what if it's not.
It changes little if anything as per your basic gambit that the placebo effect may be specific to self-awareness. Also note your exact word was "animals" not humans as per "an evolutionary selection mechanism occurring which favored animals which are self-aware enough to induce this effect........"
As to your assertion that "It's not like consciousness has arisen many times and always killed itself off. This (natural) experiment has never been run before. We don't know what will happen." Again so what if that's true, so what if it's not, and further you (nor I) do not know if similar patterns have been repeated given the extent of potential life-forms over time in the cosmos.
As to your claim that population numbers must be a measure of so-called "success" one can affix any number of meanings to the word "success", however I do not see merit in that given your claim that consciousness is beneficial to survival, and given that the only measure of so-called "success" on the level you refer to would be how well a species exponentially breeds, and not how long it can survive.
I also disagree that "We humans aren't doing anything that any other species wouldn't do if it could; expanding until our own population begins to throttle our growth." There is no way to know what "other species would do if it could" especially in light of the fact that if intelligence did develop with other species here on earth (or other planets) and if it did survive for an extended time, the mathematics of exponential growth and the logic of survival suggest it would have to learn to self-regulate its numbers.
As to you argument that "It's a perfectly natural behavior to poison your own environment until you're stopped by your own waste (bacteria did it billions of years ago and nobody demonizes them)." "Natural" is just another one of those words like "success" that can used any way you choose, and in no way infers that "natural" is either desirable or logical. You repeat this fallacy as per "natural" when you claim "Every living thing on the planet behaves this way."