OK, so I'll generate a new receiving address every day. You don't know the age of my wallet, all you can know is the age of the receiving addresses. You don't even have any idea what receiving addresses belong to my wallet. And even if you did know the age of my wallet and all of the receiving addresses inside of it, I can always just generate a brand new wallet whenever I wanted.
doesnt matter. when transaction fee is a steady function of time transferring your coins to a new address every day will cost you as much or more than just keeping it where it is.
OK, I understand where this is going now.
But.
That doesn't fix anything. If it is a directly proportional function, then there isn't really enough incentive for spending now vs later. Because it is directly proportional, all that it does is change the prices that people are willing to accept on both sides of the table. It would cause some problems early on, but eventually, the market would stabilize and you'd have to find some other way of upsetting it again.