This may be because the viscous effects are not modelled or not modelled correctly in order to simplify solving the governing equations for fluid flow numerically. I'm not sure if these effects or the absence of them would be visible to the naked eye.

That's probably because the particles in the simulation are orders of magnitude larger than real life water molecules. A lot of the tech goes into compensating for this, but there's only so much that can be done.

To be fair, this also seems to be running a bit slowed down.