In my opinion, Conquest is a format that is fun for people to watch but it has a lot more flaws than Last Hero Standing for the competitors. First of all, the argument that people use to defend Conquest's skill cap over LHS is that in order to lose to a ''less skilled opponent',” he needs to win with three different decks against you. But if you compare it with Last Hero Standing, he needs to beat three of your decks which is harder to do than abusing some good matchups on one of the decks or queueing correct matchups.
One other thing I don't like about Conquest is that preparing for a Conquest tournament is way easier than preparing for an LHS one. In LHS, you need to make sure that your lineup is not particularly weak to any deck in the meta. in conquest you should in theory target one or two decks with all your four decks which is way easier to do.
And no matter how well you read the meta, there will never be a tournament where every player runs one specific deck which can cause you to start on the wrong foot in Conquest. Last Hero Standing there's a big chance that with a lot of preparation you find a lineup that just destroys the entire field and you start favored in any series you play in the tournament, therefore rewarding your practice.
Finally, the thing I hate the most about Conquest is that the most efficient way to pick decks is to randomize your pick order. mathematically proved in countless Reddit threads. Until the point where one of the players has only one deck remaining both players have to blind pick their decks leading to some not-needed randomness which can cause a better player to start super unfavored in a particular series.
In a metagame where most of the matchups are close to 50-50 and their outcome go to either better plays or RNG, this aspect of conquest tends to go unnoticed. BUT in a meta like we have now in Old Gods, probably has more one-sided matchups than ever, Conquest is possibly the worst choice for a format.
A practical example: Player A has Freeze Mage, N’zoth Pally and Renolock. Player B has Warrior, Zoo Warlock and Priest. In this situation, Player A wants his Freeze Mage to face either Zoo or Priest, but under no circumstance Warrior. He also wants his N’zoth Pally to face Warrior, but he doesn't want to play the deck against Priest.
In this situation, if one of the players hits two favorable matchups he has a massive edge over his opponent, even though there was a chance that they would queue the decks in a different order in which his opponent would be the one heavily favored.
In Last Hero Standing, the only time players blind pick their decks is for the first game of the series. And there are a lot of situations when a player's lineup is so well constructed that he can pick a specific deck and even in the worst case scenario - where his opponent picks the absolute best counter - he is still favored on paper just because he has really good counter decks.
This way LHS drastically reduces the biggest issue with Conquest which is picking blindly. In a combo-control meta like we have now, you can expect a lot of pro players to be sad after regionals because they started a series unfavored simply because they queued their decks in a “bad” order. Since there is no way to predict how a random opponent you’ve never faced before tends to pick their decks, it's completely blind in Conquest. because they have to get a win with every one of their decks compared to LHS. In conclusion, while LHS might not be the best format, it's miles ahead of Conquest.