We have transactions fees, to avoid creating tons of transactions and increase the blockchain size to a extreme amount.
Those transactions fees are sent to the next user who is the miner.
How would the economy of a coin would change if instead of sending the transaction fee to be mined, the transaction fee was frozen and 1 year after it it would be sent back to the wallet. The user wont lose that money, but still can't keep making tons and tons of transactions to spam the blockchain.
This will not work in bitcoin, with the halving that happens every 4 years it means the rewards the miners are getting in terms of bitcoin are lower, Satoshi envisioned that in the future the miners will benefit primarily and then absolutely from the fees, and if something like that was done then all incentive for the miners to keep investing heavily in their equipment will disappear and the network will become insecure due to this lack of investment, so I do not think this is a good model to follow.