We can't take reality for granted. Most interesting things we see are simulations. For example, I see Mars. Most likely I see it on TV, or in dream, or in a book. So in most cases we need to invest to prove that the object is real, not that it is simulated. Most time we see images or dreams, not real things. So even in our world most experience are simulations. If I say you that I have a palace with 100 rooms, most likely I lie. So being skeptical means not believe in reality of anything, especially large and expensive.

Of course, it would be premature to start to believe that we are in the simulation without any practical evidence. But we should give simulation hypothesis higher a priory probability.