There appears to be a gorilla in your refrigerator room.
Anyway, many types inherently favour different aspects, either through their interactions on the chart or via moves that see low distribution outside the type. I don't think looking at just the performance of pure types is that good a metric, since I consider how effective a type can combine with others to be a noticeable part of its effectiveness and you would frequently run into the issue of small smaple sizes twisting things to focus on those mons specifically. Interestingly, I don't actually think of pure Steel as an amazing defensive type, since it has weaknesses to three common attacking types (two usually physical, where Steel usually leans towards). Steel really gets somewhere defensively when it has a secondary type or ability that can cover at least one of those, even if it eats into Steel's resistances to do so (e.g. Skarmory, Heatran, Ferrothorn, Aegislash).
Ice has a problem that its chart interaction leans heavily towards one direction, but its exclusive moves and stat distribution often ignores that. The few offensive Ice-types like Weavile and Darmanitan have done consistently well, while many defensive ice-types that did well at some point were basically reliant on a defensively-strong secondary type like water or ... more water. Rock has a very similar issue of having physically defensive statlines with a type chart that favours everything else, but many fossils or Rock-type legendaries do lean in other directions so its less obvious even if pretty much every slow rock-type is bad.
