"I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses; for whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy."
— Isaac Newton's Letter to Robert Hooke
Gravity is flawed. Be it, pulling power or pushing power, all powers effect every object the same way. If you can push a 10kg weight you can push a 1kg weight, too. If you can pull a 10kg cart you can pull a 1kg cart, too. If gravity is a pulling power, it shall pull every object with the same strength. If the pulling power of gravity is so strong that it can pull millions of tons of oceans then the same strength would be applied to all objects. Thus you could not walk, run and birds could not fly due to the immense pulling power of gravity.