You need to understand the purpose of grounding.
Originally Posted by MyMilan
Grounding provides a safe pathway for electricity that could cause a shock hazard to residents. Equipment grounding provides the grounding path throughout the house. Electricity will seek the easiest path to the earth. Your body is an excellent electrical conductor ---- if you make contact with energized equipment, you’ll become part of the circuit.
At one time ( years ago ) ground *taps* or connections from the outlet or box to the nearest cold water pipe were allowed.
However, because so many insulated or plastic devices are being installed in water lines – breaking the ground connection. In order for it to be safe a low resistance direct path to earth is needed which is not assured with ground *taps*.
It's now required that all grounding wires connect to the grounding buss bar in the main service panel.
In other words --- the grounding has to be at the main panel which includes those outlets you did last year.