Why does a star ten times the mass of the Sun have a lifespan of only millions of years?

Greater gravity requires a non-linearly higher rate of fusion to maintain equilibrium, burning fuel faster.

The initial mass of a star dictates the intensity of its gravitational self-attraction. A star ten times the mass of the Sun experiences vastly stronger gravitational pressure inward compared to the Sun. To prevent instantaneous implosion under this extreme weight, the core must generate an exponentially greater rate of nuclear fusion to produce sufficient outward pressure for hydrostatic equilibrium. While this massive star possesses far more hydrogen fuel overall, the necessary rate of consumption required to sustain the balance is so extraordinarily high—shining thousands of times brighter—that it burns through its entire hydrogen reserve in mere millions of years, contrasting sharply with the Sun’s estimated ten billion year lifespan.