Have you ever heard that older people need less sleep? Well, it may be true that a 70 year old sleeps on average two hours less than when they were 30, it's not because they don't need the sleep.
When you get up there in age you spend less and less time in deep sleep. Which means that you're more likely to wake up during the night. Plus, chronic pain or illness is more likely to wake you up.
When you're old, you tend to get less sleep even though you still need it.