Most notably, senjutsu chakra is fundamentally different from the Force in that it has different prerequisites, requiring one to balance and mold their inner chakra with natural energy by remaining perfectly still to draw in the energy first. Simply opening oneself to natural energy opens up the possibility of the user changing shape into an animal and petrifying at the same time. Attempting to absorb a Sage's chakra can turn another to stone. The Force has no equivalent mechanic/caveat, requires no mixing with another internal energy, and while Force sensitivity is a genetic trait, with multiple notable Force Sensitives that figured out how to control their Force abilities on their own, the ability to absorb natural energy and create Sage Chakra has to be strictly learned (unless you get the bite from the Great Snake Sage, anyway).