It's interesting that you got the idea of trashing coppers more quickly than trashing Estates. That's great! Some in my playgroup trashed their estates quickly, but had a hard time learning to get rid of coppers because of their buying power (such as it is.)
What you might want to do is read some of the game logs and see some high-level players at work building engines. Once you see a turn 15-16 that draws the entire deck, plays the entire deck on the table with virtual coin, extra buys, cost reduction, and just a handful of actual treasure cards (if any) and then buys 5-6 Provinces all at once, you'll see the light. Estates and Coppers just slow you down. Check out some games with Chapel and you'll notice that most players will immediately trash their entire hand as soon as they draw Chapel, sometimes twice, picking up perhaps a Silver and a Terminal +$2, +buy action card along the way. Once your deck is tiny, EVERY hand is a good hand, and that's the whole key to Dominion: Not wasting turns on lousy draws.
The game log point graphs also tell the story: A well-built engine scores no points for turn after turn, building and building, and then explodes in just a few turns at the end (or buys everything and ends the game with a mega-turn.) Estates can only hurt that process, and the 1 point you get from them is utterly insignificant.
One other quick note: The term "junking" is typically used differently here, if I'm reading correctly. "Trashing" is what you call removing a card from your deck permanently and putting it in the trash. Chapel is a Trasher. "Junking" is the act of putting bad cards in the deck to slow it down. Witch is a Junker. For clarification, a "trashing attack" is one in which other players trash your cards (Saboteur.) A "junking attack" is one in which they give you Curses, Ruins, or even Estates and Coppers (in the case of Ambassador and Mountebank.) There are very few self-junkers! (Death Cart)
That's one of the most telling facts about the Estate: Ambassador is one of the most powerful attacks in Dominion, because it allows you to get rid of up to two Estates at a time...and gives one to each of your opponents. If player 1 plays Ambassador and player 2 doesn't, player 2 will be buried under an avalanche of Estates and Coppers and will forever be drawing hands like Estate-Estate-Estate-Copper-Copper.
There is a time to buy Estates, mind you. It's always available as the cheapest card in the game, and may be a key pile to empty intentionally in order to force a three-pile ending to win the game while you're ahead before the Province pile gets any lower. But the opening estates are poison. Rid yourself of them as quickly as possible.