Technically so is falcon 9, but they can’t return and they have to be totally dry with no cargo, and definitely not a terrarium full of humans. Falcon heavy is even capable of going to Pluto. But it wouldn’t be a very interesting mission. More interesting would be launching unmanned probes.

Regardless, the plan is to use starships to build a LEO refueling platform and bring propellant for a lunar lander brought to orbit via a starship. Such a platform could also be used for Mars. It’s a much smarter move than trying to bring everything from earth in a single shot. And I can vouch for the sanity of the plan - I have almost 600 hours on KSP which makes me a bit of an expert ;-)