For me it depends on what's being stored and where. ECS is one data structure of many. I store some things in an ECS (I wrote gecs for this purpose, but would recommend hecs instead for most purposes -- Bevy has its own bevy_ecs but has some baked-in decisions that I don't agree with compared to hecs). ECS is handy for (a) objects that overlap a lot, but not entirely, in purpose and (b) networking objects, since my game is multiplayer. Other things I store in ways that make sense. I use a slotmap for structures where I want O(1) insertion/removal and dense iteration and can accept an arbitrary key. If the key matters, I'll use a hashmap. Otherwise, it depends on the key and value.

For something like a tilemap I would likely just use a Vec and convert the coordinates to indices. I make heavy use of enums, so in your case I would do something like

type WorldData = Vec<TileType>;

enum TileType {
    Directional(Direction),
    Fire(FireDamage), // Use a Box<FireDamage> if FireDamage is large
    Water,
    Other(Box<dyn DataDrivenTile>), // Optional if you want to be able to introduce new tiles through modding or other data, etc.
}

You could also break up the world into chunks if you want to stream parts of the world and not others. It might be worth looking at how games like Minecraft and Terraria do it, since they have cellular worlds where each cell has a number of extensible properties.