Ethereum has 16m volume daily which is too high compared to Tron so I think it is long long way to go before ETH can replace Tron.
And there is a big news about Ethereum recently and there is a big incoming adoption so it is hard to say that TRON can replace ETH.
That volume really makes ETH a top altcoins and I dont see any threat right now aside from XRP. There will be more coins to beat for TRON before placing next to ETH so its not possible for now. ETH makes a big announcement, its price pumps higher that can continue up to the real bull market. TRON have to take all the challenge or else, it will be failed and I think the goal is not to be a top altcoins but to provide good services to all the crypto enthusiast.