Here is the parts breakdown.
Replacement parts for General Electric GSD5560G00SS Dishwasher | AppliancePartsPros.com

You did not mention any problem with drying so I am assuming that the water is heating up and the heater etc. are OK.

Remove the sump cover (center of tub) and check that there is not debris or something wrapped around the chopper. Be careful, there is often glass in the sump.

Check that the screen filter is OK.

Check that the holes in the washer arms are clear.

Often this is a low fill situation. Often you can hear this, the pump will make a growling sound because it is sucking in some air. It should fill to just under the heating element.
A quick way to check this is to add a couple quarts of hot water after each fill during a cycle and see if it does a better job. Just be careful not to overfill it.
If it is low fill the most common causes is a partially clogged filter screen on the input side of the water inlet valve. Remove the valve from the unit and check/clean the filter. Do not permanently remove it from the valve as it is there to keep crud out of the valve which could hold it open and cause a flood.