Question

You have said that atmospheric pressure can be controlled by a human body but why can't it control the weight of a solid

Answer 1

Our body has evolved to cope with the atmospheric pressure on earth. The pressure of air in your lungs nose and ears are the same as atmospheric pressure. Thus equlibrium or equality of forces are achived. At a given height pressure due to fluids are equal at all directions. Thus it is easly cancelled out by the evolved body of humans. But lifting a solid weight imposed several dynamic forces on the muscles and this cant be solved by evolution. We have to balance out with the muscles that can also deal with several other weights. Muscular forces are dynamic and force due to bofy pressure is relatively static.
this is the reason why if you go to space without spacesuit the fluids in your bofy will get instantly vapourised and you will die due to pressure leak.