Is it okay to directly connect the copper wire to the ground if the toilet equipotential is not conn

Grounding wire and equipotential connection are two different concepts. In layman's terms, equipotential bonding is the interconnection of various metal bodies to form equipotential bodies.

If you can ensure that the grounding resistance of the direct copper wire grounding is less than 4 ohms, and then connect the root wire to the power socket, which forms the protective grounding wire of your home power supply, but it is difficult to ensure the grounding resistance and reliability of the grounding wire you make yourself.

The circuit of the electric water heater should be switched with leakage protection, which is more reliable.

Screenshot of the code for electrical design of residential buildings JGJ242-2011<> 4 ohms is 4 ohms, the practice of regular grounding electrodes:

This depends on the type of building you have, if it's a rural house, there's no problem. The main function of equipotential is to make the voltage of all parts of the building equal when encountering a lightning strike to prevent ignition. If it is a high-rise floor, there may be unequal potential because of the grounding alone, so it is overlapped on the steel bar nearby.

In rural areas, small houses can be picked up separately, but in the end, they must be shared with the house.