Yes people do tend to sleep less as they age.
When we are babies we usually sleep 10 to 14 hours per night and day because the babies need more sleep to grow and thrive.
As the baby gets older and reaches 2 to 4 years old then they may only sleep for 10 hours to even as little as 8 hours but sometimes they may still sleep up to 12 hours.
Then when they reach 5 to 8 years old they may only sleep 8 to 9 hours per night and as we get older we may only sleep for 7 to 8 hours per night.
Then as we get even older we may sleep only 6 to 8 hours per night depending on how tired the person is.
After we reach adult age we don't tend to sleep much less than 7 to 8 hours per night but some people only get as little as 5 to 6 hours of sleep.
According to research the 7.5 hours of sleep is better than 8 hours of sleep.
There's no requirement to actually get 8 hours of sleep unless you really need the 8 hours of sleep for yourself to function.
Most people today get only 6 to 7 hours of sleep per night and they function just fine.
Even people who get only 6 to 7 hours of sleep live a long healthy life without any health issues.
So as long as you get at least 6 hours of sleep or 7 hours of sleep then you should be just fine.
I sometimes only get 6 hours of sleep and I'm just fine however sometimes I need to get 7 or 8 hours of sleep on some nights when I'm really tired.