"Illusion" isn't synonymous with "construct," though. A construct is something that's been built. Everything we perceive in nature has been constructed (evolved and complexified), and those constructs are real enough. They're illusory only if we forget their elementary and quantum underpinnings. The constructs we perceive aren't the whole of the story, just as the mental self we're familiar with in being ourselves is a poor substitute for the brain. But that doesn't mean the mind is unreal. So discarding the mental self would be anti-humanistic.

Moreover, this self is only the messenger bearing bad news about absurdity. Somehow ignoring our mental capacities for reflection wouldn't change the scientific facts of nature's wild foundations.