Not a good reason, though. We all accept the reality of the outside world because to do otherwise would be impractical. The Taoist sage Chuang Tzu, for example, told the story of falling asleep and dreaming he was a butterfly. In the dream, the butterfly fell asleep and dreamed it was Chuang Tzu. On waking, the sage could never be sure whether he was the man or the butterfly, or if he was awake or asleep. Bringing that into the modern world, there really is no way anyone can prove they are awake or if they are dreaming. Things in dreams seem 100% real, just like in waking life. So you could hook up an EEG machine and show the active state of your brain and say, “see? I’m awake!” But you could also dream about an EEG machine and a diagnosis of wakefulness. There is nothing you can experience awake that you can’t also experience asleep, so there it is. Whatever “good evidence" you have that there is a world outside your brain could be dream evidence, and there is no way to prove otherwise. Which, to me, means it’s not really “good evidence.”
My point is not that nothing is real, but rather that all schemes for dividing human experience between the “real” and the “not real” are arbitrary and usually based on cultural prejudice. 21st Century culture is highly biased against spiritual experience and in favor of interpretations of reality that define the physical as real and all else as fantasy. But those are just biases. Thy don’t say anything about reality as it is.
