My understanding is utxo is like bills so if you have a lot of utxo you have a lot of bills and when you make a transaction the fee will be higher because you need to pull more bills together to make the amount that you want to transact with.. so if you consolidate your utxos to larger amounts and less your fees will be way less.. if someone else can add of correct if I'm wrong because I'm learning this now lol 😆