It is very intuitive to believe that sentience motivates us to make (better) decisions (“better”, from an evolutionary point of view).
But we can also consider that it is possible that we are sentient robots, but without will, that we simply do what we have been programmed for, even though we have the feeling that we make free decisions, so that sentience really does not play any role in the evolution in form of motivation.
If there is no will, then the apparent motivation produced by sentience would also be an illusion. Sentience would be a byproduct of certain physical conditions, or something ubiquitous (Panpsychism). Sentience would appear to be evolutionarily useful, and yet what would be evolutionarily useful would be such physical conditions.