Evolution selects for immediate survival. Because intelligence is expensive, competitive species evolve enough intelligence to compete with each other. But the extra intelligence needed to guarantee successful long-term management of an entire planetary ecosystem is at the far end of the bell curve, and most individuals won't be capable of it. Likewise for effective off-world colonisation.

So you get a race between the self-destructive effects of short-sighted individual intelligence pursuing the usual goals of fighting, fucking, and accumulating resources, and the amplification effects of whatever collective intelligence mechanisms a species can evolve.

At the moment we're not doing so well with the latter. It's going to take a phase change to move collective intelligence up to a level where the likely default is long term survival.