A large potted plant is really a moving problem in two parts: an awkward heavy pot and a trunk or canopy that can snap if it takes the wrong hit. Tilting and rolling instead of lifting is what saves your back and the plant.
Pro tip: Two people can walk a large pot on a furniture dolly by tilting it slightly and rolling rather than trying to carry it flat.
Watch out: Never drag a large potted plant across the floor; the pot can crack and the sudden jolt can snap surface roots or the trunk.