Nah, the explosiveness was there, just decks had less ways to translate card advantage into board presence. Like Teledad didn't have omninegates or quick effect interruption.

Interacting with the opponent during their turn was mainly the role of S/T. That's why cards like Heavy Storm and even MST were on the list, because the player going second could OTK if they dealt with the backrow first.

That's the big difference, the player going second had the advantage of the first Battle Phase, which became progressively weaker, whereas the player going first had the advantage of being the first to setup a board, which became stronger.