in that case I'd be interested in hearing what are the 23 3$ers that you esteem worse than Trade Route.
Chancellor, Great Hall, Woodcutter, Fortune teller, Masterpiece, Sage, Workshop, Banquet, Caravan Guard, Tunnel, Storeroom, Oasis, Oracle, Smugglers, Farmer's Market, Shanty Town, Chariot Race, Gladiator (not counting Fortune), Wishing Well, Guide, Expedition, Enchantress, Market Square, Warehouse are the cards I'd say are weaker, in the order from bottom to top. I made this list by going to Qvist's 2016 rankings, starting from the bottom, and for each card, asking the question "is this weaker than Trade Route?". I didn't keep track of how many I already had and I didn't actively try to get to 23. It's funny how close it turned out to be regardless (in case you don't want to count them yourself, I got 24). I briefly considered including Develop but decided against it and I'm very confident that my decision was correct, and I briefly considered skipping Scheme, decided against it, not super confident in that decision.
It's interesting that the only cards I skipped were other trashers (and obviously TR itself).
What's also noteworthy is that there are a lot of $3 cards that are extremely strong, because there are so many trashers there. If I repeated this with all the cards in Dominion, I'm pretty sure Trade Route would end up in a higher percentile.
If Forager and Trade Route are both available, it doesn't make sense to call Trade Route a power card. Since Trade Route loses on most of these comparisons, it's called below average.
Exactly, and I'm saying it shouldn't be the case that it's called below average just because it loses on most of those comparisons.