Snorlax is a huge check to most things. Without it, Nidoking, Zapdos, Raikou, and Jynx require a much more intentional defense. Things you wouldn't think of as offensive threats because Lax covers them so well, like vanilla Starmie, also start to require mental bandwidth to handle in the builder that you normally wouldn't even need to think about. You also need to be more intentional about how you cover Gengar and even something like Mixed Ttar. Alakazam becomes a terror unless you run one of Blissey, Ttar, or Umbreon.
Lax isn't unique in covering all this, of course. But you'll need a committee of Pokemon to cover everything. Plus, on top of needing more teamslots, that committee will end up ceding a lot more momentum than Lax does. Lax forces really passive play in a way nothing else really can. That means you're spending more turns reacting, potentially even reeling from the lack of "reset button" that Lax provides, and fewer turns trying to make progress when using Laxless.
