Transaction age shouldn't be a factor here to consider for adding into a block. It would minimize the number of people getting interested in mining Bitcoin, turning it into a less decentralized network. I'm not an expert when it comes to the technical aspects of Bitcoin so I can be wrong with my assumption.
Age used to be an important factor, back when the vast majority of transactions did not pay any fee. The more confirmations an input had before you spent it, then the higher the priority given to that transaction. The other factors taken in to account were the amount being spent (higher amounts had a higher priority), and the size of the transaction (smaller transactions had a higher priority).
But of course none of that is relevant any more, and miners prioritize transactions solely on the fee rate that they pay.