Animals have three modes of being: active, passive, and broadband. Non-selective or broadband sensing evolved for the purpose of being receptive to and aware of sudden movements and changes in the immediate environment. Broadband sensing can only be done now. Animals need it to survive.
Non-selective is not a good word to describe it because this fails to describe the actual activity of being ready and on the watch, or ready to be watchful.
Broadband sensing evolved as a balance for focussed activity, and while passively dozing. This is a vital part of the oldest, original, most natural form of being awake and staying alive.
Humans balance their active focussing mode with sleeping, and sometimes seeking inner peace; but modern man hardly ever uses this third mode of being, our broadband mode.
Could we be missing out on something?