Honestly, I'd argue that the belief that we do have free will and accountability to our actions can be a deterministic factor that at least inspires you to do certain things that you wouldn't have done otherwise, regardless of whether we actually have free will or not.
Thing is, if this universe and our actions are deterministic (and the evidence at this stage in time points towards yes) I think it in itself puts accountability to our actions as a species, considering that humans through cooperation can directly affect the environment around us, it's our duty to at least attempt to create a better environment for the world and people around us.