The accumulation/fusion of heavier elements within stars is a by-product of the process that leads to a supernova, not the other way around.
Stars operate by Nuclear Fusion. They fuse small elements to make larger ones, using their (predominantly Hydrogen and Helium) fuel. when the star runs out of a fuel, it gets hotter and uses a different (larger) fuel. Because there is less of each consecutive fuel, each consecutive stage lasts less time.
While in the very final stage the very core of the star is fused into iron as is tries to resist the outward force, eventually it can't and goes supernova, forming everything else up to Uranium.
So yes, while Iron is the core of the star for a bit, its still a minority to the H/He/Other elements and this only lasts for a few days, compared to the few billion years a star lives.
Also I'm someone will jump in and "um actually" me.
Also this thread should be for pokemon.
Solgaleo is pretty awesome and objectively better than Lunala, I just wish they had been swapped in their abilities, so Solgaleo with the good typing (especially defensively) haad the great defensive ability and Lunala with its good offensive typing had the meh ability.