On the other hand, Coppers and Curses are strictly worse than Silvers on most boards, even by your definition.
But nevertheless guided's question is valid, I wanted to ask the same thing. "Worse" is just not a attribute that's definined well enough. I can live with the common "strictly worse" like "striktly better" (ignoring price, trash-for-whatever, pile-endings, embargos and other special cases), but that's as mentioned only Copper and Curse. Which I think would in this case better to be spelled out explicitly, as they are only 2 cards and then it's totally clear what's meant.
So maybe we just name the cards we think will meet the description (and maybe why), and in which situations you would prefer them over Silver.
Copper:
- Coppersmith/Counting House/Apothecary
- Silver is embargod and some rare cases where I need one more additional coin in my deck.
- Maybe some rare cases with HuntingParty, all Coppers trashed and I need one more additional coin to be hunted for.
- Also rare cases with Menangerie
- When I'm possessed I also "should" buy a Copper over a Silver, annoyingly it's not my decision...