This is a remarkably well written critique of scientism, imho. Well structured, concise, on-point philosophical arguments. Great that you brought in McGilchrist -- very relevant.

I'm fairly content being a biological creature. I'm fine with Being being a complete mystery. I'd say our "purpose" is merely to survive, that there doesn't need to be anything more, that what our minds create is more than enough to make life fulfilling.

The right hemisphere for all we know has a rich life, even if it can't share it with the left hemisphere, which should be content with what it has.