One hundred kilograms of weight can be lifted easily by one person without much effort. Why?

Because there are "industrial manipulators" to help!

This novel industrial equipment is used for labor-saving operations during material handling or assembly. It cleverly uses the principle of force balance to enable the operator to push and pull the heavy objects accordingly, so as to balance the movement and positioning in space.

With it, people only need a small operating force (a few kilograms) to carry or operate heavy objects of tens to hundreds of kilograms.

If you choose an industrial power-assisted manipulator, look for MOOPEC!