I went to setup my iPad, and it had an option to add multiple icloud accounts! I don't know if this is equivolent to user profiles, or just munge all of icloud data like notes, contacts, calendar, apps all together
after using both for the past 5 years, I'd say the main difference between peotry and uv is user experience and documentation. Poetry fought me every step of the way w.r.t. pip migration, venv, poetry updates. uv just worked in these areas, which meant I was updating packages much more frequently, which increased my experience and confidence in uv for a virtual cycle.