I think when we read this passage, we often become so focused on the number of years it's mentioning - the sheer length of time some of these people lived. Read over it again, I think there is something else that's important to note in the whole passage, more important than the lifespans recorded.
Notice it?
In verses 5, 8, 11, 14, 17, 20, 27 and 31 it mentions the lifespans but each verse ends with the words "and then he died."
I think that the more important thing to note here is that in each case, they lived for a while and then died.
I think an important point to take from this passage is that, as the Bible says in Romans:
and in Romans 5:
This sin entered the world by Adam's disobedience:
So this passage actually demonstrates that what God warned in Genesis 2, has now come to pass by Genesis 5.
Thankfully, though, God has provided a solution to this problem. Returning now to Romans 5:
The obedience of one man referred to here being Jesus's obedience and accepting the punishment that was due "all men" even though he himself was innocent. While we were still stubbornly turning our backs on God, Christ died for us.