What others do, is not my concern in regards to:
"that some disguise as mystical magical invisible powers",
every field has its imposters and marketers.
Ki as defined as a life force, is practical.
Ki energy described as the flow of water through a fire hose, preventing it from bending, is common sense.
Our bodies are over 80% water.
Would the mechanistic describe our movement in terms of bones, pulleys and tendons?
When I see a tiger move, I see a wave, not a stick diagram/erector set of pulleys: a mechanistic approach.
If you want to talk physics, kinematic wave theory as studied in the models of wave propagation theory or the piezoelectric effect in this forum, under Non-mystical discussion of Qi