I think it would be great to try out things that are impossible in the real world without any risks. Not necessarily crazy things, but things that are just not available to me irl. Like designing stuff without any limits of ressources or money. That way we could improve the real world by testing things in the virtual.
It quickly turns into a philosophical question of what you really want to do in the real world and why. It doesn’t make much sense to better your real world for things that could be easily done in the virtual. However, since your life even in the virtual world depends on your real survival, there would still be things to do.
Then there’s also the thing that your virtual world would be limited to your own imagination. At some point, that will get boring even with virtual people around. It would still make sense to exchange ideas with actual people in order to expand your own virtual world.