Didn't know gravity forced anything to do anything
You forgot, in Newtonian gravity[1] that mass accelerate other mass, hence it force all particle with mass to accelerate towards the center of mass.
Also, as we know our Earth isn't made out of pliable plastic or paper, it is multiple layers or hard stone, crust, iron, magma, giant volumes of water etc.
Irrelevant on something very massive and dense
To assume it should just fold in upon itself is illogical
But it doesn't fold itself "compressed" into a sphere is a more correct term. Also the Earth didn't form as a flat disc in the first place.
Big Bang doesn't have any actual hypothetical mechanism on how a multi layered sphere with varying, yet perfect amounts of periodic chemicals happened to form out of an explosion.
A common creationist mistake to attempt disprove complicated stuff by the Big bang, the reason the Earth is denser in the center is because of buoyancy[2], the heavier iron will fall to the center of mass and the lighter element to the crust.
[1] General relative refined that gravity is actually not a force, but a result of bent spacetime. But this is irrelevant in the current discussion since we're arguing about Newtonian gravity.
[2] You know how buoyancy works, so i expect no question regarding of buoyancy in spheres.