If the proton and neutron did not have enormously greater mass than the electron, all matter would be fluid and there would be no planets, no stars, no galaxies and no life.
How do you know that life is not possible in a fluid state?
1.1 Fluid Mechanics
Fluid mechanics is the branch of science concerned with moving and
stationary fluids. Given that the vast majority of the observable mass in the universe exists in a fluid state, that life as we know it is not possible without fluids, and that the atmosphere and oceans covering this planet are fluids,
fluid mechanics has unquestioned scientific and practical importance.