Copper and scout are close but I think scout might be slightly better?
In the case of playing scout and drawing no victory cards, it is actually worse than copper.
Playing scout and drawing one victory card, it is marginal (cycled one dead card but effectively did nothing) so I'd still say worse than copper given that you took the effort to add it to your deck.
Playing scout and drawing 2+ victory cards, it is probably better than copper, but not by much.
This is all assuming that you're unable to do anything with the top-deck inspection, but it's quite unusual to be able to get enough value out of that to push the balance in Scout's favor.
So most of the time Scout is worse than copper.