https://www.inaturalist.org/flags/694515

For most of the 20th century the name "V. palmata" was thought to apply to plants consistently producing lobed leaves throughout the growing season. "V. triloba" was used for plants that produced unlobed leaves in early spring (and sometimes also in autumn).

In the 1990s, several botanists independently realized that the names "V. palmata" and "V. triloba" had been misapplied: it turned out that Linnaeus's "V. palmata" actually had some unlobed leaves, so this name should have been used to refer to such plants. "V. subsinuata" was chosen as the replacement name for most of the plants with always-lobed leaves that "V. palmata" had been referring to.

Most iNat users seem to be using these names in the post-1990s sense, anyway. My suspicion is that much of the continued use of "V. triloba" is meant to indicate the shallow-lobed variety, V. palmata var. triloba. But there are also plenty of observations with deeply-cut leaves as well.

Also, some observations of plants with all leaves deeply-cut currently have iNat identifications of "V. palmata". These IDs might reflect the older use of the name, but they could also indicate a preference for a broader species concept.

See the flag linked-to above for more about the varieties, some information about active research on these plants, and the rationale for including the varieties despite Kew's POWO not having pages for them.