What if Earth was the largest gas giant in our solar system?

So I've often heard the fact that Saturn is the only planet in our solar system that could float. It can't, because Saturn isn't a gas, so it can't float in water. The reason it can't sink is that it's buoyant enough. There are a few reasons for this. Gas giants are mostly H^2 and He while Earth-like planets are mostly composed of heavier elements, gas giants have a lot more mass than Earth-like planets, solar composition, atmospheric composition, etc.<br><br>I got to thinking, what if Earth was the largest gas giant in our solar system? Would we ever have been able to colonize the planet? What would we do instead? Would we still have civilization as it is today? What are the implications of this?