I’ve played a bunch of Catan. The included wooden dice are all terribly biased. Not in the same way, but enough that a sets owner knows, at least subconsciously, what numbers their set favors.

The best way I’ve found to mitigate this is to have a bag of assorted dice with the set. The various sizes and materials, with a swap out at every game, makes sure the dice bias isn’t predictable.

Regarding dice decks. I find they make the game sterile. A near perfect bell curve means you can anticipate number droughts or floods, aiding in robber strategy.