Treat utxos like bills in your wallet. You wouldn’t want to only have $10,000 notes. You want some $10 notes to buy a coffee with and not get $9990 change.

I think aiming for 1M utxos for the better part of your utxos is a good practice. Maybe also some bigger ones if you want / can afford. But maybe also some smaller ones in case 1M would be overkill