Floor space and territory aren’t the same thing. A tall corner tree for households with wall space to spare, and a genuinely compact tower for the smallest studios and rentals, plus how to fit either one into a small footprint without it taking over the room.
Yes, or some equivalent vertical space. Apartment cats need height to feel safe and use their territory. A wall shelf works too.
The practical playbook for indoor cat behavior and enrichment: what cats actually need, the highest-leverage setup changes, and when behavior is a vet visit.
A small apartment can hold a lot of cat territory if you build upward. The apartment-design guide to vertical space.