4 reasons come to mind:<p>1. Advanced societies have probably solved the aging problem, leading to either extremely long lives or effective immortality. As long as these societies keep reproducing (and they will, unless they deliberately engineer out the urge to procreate, which I consider to be unlikely), they&#x27;ll need space to spread out. Sure, they could probably pack themselves like sardines into a single solar system, but that only works if they&#x27;ll be spending 100% of their time in virtual reality, and that would be begging the question.<p>2. A need for resources. Type III societies can capture 100% of the output of a star, but even this amount of energy might not suffice once society grows large enough. And even at that level it&#x27;s still probably easier to manipulate matter than it is to convert energy into matter, so it&#x27;ll be more efficient to harvest planets and asteroids and whatnot for raw building materials, which means leaving the solar system.<p>3. Even assuming they manage to create virtual reality that is 100% indistinguishable from reality, it&#x27;s likely that there will still be a lot of beings that will reject the idea of living 100% in virtual reality simply because it&#x27;s virtual. Even if it&#x27;s indistinguishable from reality, they&#x27;ll still know it&#x27;s not real. So they may visit VR, but will want to actually live in the real world. Or in other words, humans have shown a tendency towards the perverse, and it&#x27;s not unreasonable to assume aliens will too.<p>4. Any kind of scientific research still being done at that level will likely require the use of reality instead of VR. VR is a simulation, and even if it&#x27;s indistinguishable from reality to your senses, it&#x27;s still presumably not actually simulating reality down to the planck level (because it&#x27;s part of the universe, it cannot simulate the entire universe at the same fidelity that the universe itself operates at, as that would presumably require more information than the universe contains), and so there&#x27;s probably a fair amount of research at that level that simply can&#x27;t work in simulation and requires testing against actual reality.