The question of the title, why demo account always better than real account. There are some reasons about this I think. First, that's usually because of our psycology. If we used demo account, when condition is loss, you still have confident that condition is back to normal and you gain profit but in real account, your confident usually decrease when the loss points was greater and greater for long time, actually usually it's not too long. It's normal because in demo, nothing to lose but in real account, you lose your money. Secondly, usually because of equity in demo account is bigger than real account so they could stand even if the price was decreased much.
So I think the main difference between demo account and real account is not real money or not but psychology. we have totally different attitude to demo account and real account. I think they are the same if you treat them with the same attitude.