This paragraph is vital:
A usufruct is either granted in severalty or held in common ownership, as long as the property is not damaged or destroyed.
This means that most things aren’t owned by one person (legal or natural).
Being a landlord is based on the third property relation:
The third civilian property interest is abusus (literally abuse), the right to alienate the thing possessed, either by consuming or destroying it (e.g., for profit), or by transferring it to someone else (e.g., sale, exchange, gift).
Abusus isn’t only about destroying, but also about keeping something from being used (A landlord can keep me from living in their house, unless I pay them).
If you don’t have the abusus right, you simply can’t keep others from using things. Which is why most property would be held in common. Think of it like a big library for everything. Not only books, but bikes, pots and pans, tools, furniture and accomodations.