I think it's 3 things for me.
In a perfect healthy world, there's one spot in the lineup where you could foresee the benefit of having Tauchman PH (catcher). And that's before we potentially try and upgrade that position. And that's also before the idea of getting a lefty masher, who further reduces that opportunity, or trading/for signing a true starter bat, which pushes a current starter to the bench to take those PH spots.
In a regular injury world, you still have to gameplan out pretty pessimistic scenarios where you'd be like 'man, I really wish we had Mike Tauchman'. Suzuki could slide back into the outfield, Caissie is knocking on the door, Alcantara isn't far behind.
He's still good, and has value for a team that needs a cheap 3rd/4th outfielder. We don't need those things, but we need other things. Trade him.