Jupiter used to be TWICE its current size

No it wasn't

Jupiter is a gas giant like Saturn, Neptune, and Uranus with no solid surface like Earth!

Even earth is shrinking very slowly as its core cools. Similar to how a hot piece of metal shrinks as it cools down.

Does fitting twice as Earths inside of an old Jupiter twice as big? Pretty sure that’s not how volume works.

Yes but no storm lol

Didn’t we know this years ago?

If Jupiter was twice as big at one time why didn't it become a Sun?