Transmute is not worthless, It's a matter of your strategy and what's important to you.
I'm up to the eastern swaps and I still run into a lot of 10-50 coin items like thin caps and linen garments.
And rather than waste the space for a 10 coin item I transmute get a couple of coins and retain the space for more valuable cargo.
But I don't immediate sell everything I collect either. I keep alot of items on my packmules so that when my characters level I don't have to wait to buy them weapons & armor which are quite pricy. And spells break the bank.
I bought a medium cross bow from the travellers because at that point no one was droping them. That cost me 52K. For 1 weapon.
I keep and eventually use all the good stuff I pick up.