Yes abundance of time cheapens it's value, but remember that some people don't even realize that time is limited to begin with. The child doesn't know that he is mortal, but that lack of knowledge doesn't make him downplay the value of time and existence completely. He can still enjoy life even if he thinks life is endless and time is abundant.
But indeed when people get older and realize life is short and there's always a shortage of time, they get anxious and value time a lot more.







