It sounds like you read that from biased people. There's no way the game is categorically better. It does some things differently which may appeal to some, and there's always your segment of anti-Blizzard people who will insist that anything is better, but ESL is not a superior game in any meaningful way. For one thing, it's so new that it's two years of card additions behind HS, making it almost objectively inferior in that regard (even though that's not a design difference) because you just haven't got very much content. That'll take quite some time to catch up to. Another thing is that they copy so severely from HS that many aspects of the game can't be better simply because they're identical.
After my initial impression, I tried the game for a few more days and my verdict didn't really change. The developers have been so afraid of designing complex spells and unique mechanics that they've pigeonholed gameplay into this template of curving out with minions, playing some fairly basic removal, and then hoping you draw better. There are faster or slower variations of this theme, but I simply never saw a deck that was actually different. If I want to play something like HS's miracle rogue or freeze mage, the cards simply do not exist. In that regard, I think the cardpool is more primitive even than HS's classic set. This, coupled with the general weakness of spells, basically sentences this game to a life of almost entirely minion-based gameplay.
I've looked through all the popular decks and studied the entire cardpool, and there's nothing besides that. The entire game is designed around playing minions on curve, either small or big ones, and then using a bit of removal to attempt to maintain board control. I couldn't see the building blocks for any other kind of deck. You can be more aggressive or more defensive, you can play little removal or a lot, you can try to include card draw (for which the options are pathetic and wildly unbalanced) and then that's about it. When it costs eight mana to clear one lane, or four mana to deal four damage to a target, you're forced to rely mostly on a steady stream of minions.
RNG-wise, it's difficult to quantify whether or not ESL's Prophecy mechanic (together with the numerous cards that have random effects) adds up to as much RNG as HS has. There's plenty of it, though, and it's presented in a really irritating way that not only rubs it in your face but also directly fucks with gameplay by punishing the pursuit of the game's only realistic win condition: attacking face. There's some merit to the idea of discouraging mindless aggression, but that discouragement should not come in the form of gambling. You either attack anyway and just hope your opponent doesn't get lucky, or you flood the board to set up a one-turn kill that's nearly impossible to stop because the board clears in this game are absolutely pathetic.
So my conclusion is that it's a game which is too similar to HS to really offer a new experience, makes the same mistakes of forcing RNG into the game and designing toward a samey meta of curveplay and board control, and is lagging behind HS by two years of card additions which means it'll be a long, long time before ESL is actually even able to realistically compete due to the limited cardpool. The game is every bit as expensive and grindy, because while it's a bit more generous with the leveling rewards and such, prices are otherwise the same while featuring 50-card decks with up to three of even legendary cards, and there are hardly any neutral cards so each deck basically needs to be crafted fully from scratch as opposed to HS where you often have the neutrals already.
