Consumer-level electrical portable cords come in a variety of types (and gauge, but that's not the subject here) and each must have its rationale, considering the cost constraint (performance/price sweet spot) and environmental use cases (exposure to water/oil/others liquids, abrasion, visibility, temperature...).
I have a hard time finding out a good reference (the most appropriate wikipedia page is poor on pointers) on how these standard cord types came to be, and how a product designer would choose a particular cable type over another.
- SVT/SJT cables are used for computer power cords;
- HPN cables are used in North America on kettles and toasters;
- I've seen electric irons with cotton-braided cables, I'd expect them to have constraints as kettle cables, plus mobility;
- lawn mower cords are typically SJTW with flashy colors (not green...);
- extreme temperature car block heater cables are STOW, it seems that rubber starts to go hard at -40°C
- household vacuum cleaner cords are often SV (and often at the gauge limit but are pretty long and tend to be used for a few minutes only...) while garage vacuums are using SJTW (also with bigger gauge in my experience);
- SJOOW seem to be used in construction