Do I need to change my power steering fluid?

Just recently got a 2001 Subrau Outback and im wondering if my power steering fluid needs changing. My friend thinks it needs changing as we have both driven it and the turning circle feels a little stiff. I have driven my friends 1999 Subaru Liberty quite a bit and in comparison his cars steering feels much smoother.

If im noticing a difference between the two is it most likely the steering fluid that is the problem? The Outback is feeling like its having trouble staying centered on the road and i feel like im almost constantly making small adjustments to stay straight on the road, that and the general steering feel is slightly janky in comparison to the Liberty.

Anyway I have checked the owners manual and the fluid reservoir appears to be at the correct level. Just wondering if I need to flush it and put in completely new fluid. Can power steering fluid even go bad?

Sorry if this is a noob question I'm relatively new to driving and this is my first car