You might consider submitting a Feature Request topic to the forum, asking to allow filterable taxon-level “fields” to be created by the community, analogous to the observation-level fields that currently exist. I can’t promise that staff would decide to implement the request, but it’s worth a try.
Observation fields currently don’t involve a “vote” - any user can add a category, define values, and assign a value to an observation. I’m guessing there would be less appetite for a more complicated system analogous to Identifications, where community agreement would need to be tracked.
Speaking just for myself, I could see a taxon-level “Life Form” field being very handy for plants, with multiple values allowed (annual, perennial, tree, shrub, carnivore, succulent, vine, parasite, epiphyte, etc.).