However, on an astronomical scale, gravity does dominate over the other forces. There are two reasons for this: 1) gravity has a long range, and 2) there is no such thing as negative mass. Each force dies off as the two objects experiencing the force become more separated. The rate at which the forces die off is different for each force. The strong and weak nuclear forces are very short ranged, meaning that outside of the tiny nuclei of atoms, these forces quickly drop to zero.
The earth and sun are far too distant from each other for their nuclear forces to reach each other. In contrast to the nuclear forces, both the electromagnetic force and gravity have effectively infinite range and die off in strength as 1/r2.
So when we say that gravity is the weakest of the four forces it depends on where and how it is being compared. We already use gravity in numerous ways via an intermediary such as water, and in the case of Bessler's wheel the intermediary is a system of weights.
If one of Bessler's four pound weights was dropped on your foot, you might not think gravity was a weak force.