With some plants, yes, with a lot of others, no. And now and then you’ll find plants with leaves that will root, but don’t produce any plantlets. Many hoyas are like this.
H. kerrii has big, heart-shaped leaves that are potted up and sold as Valentine’s novelties. They can live for some time but you won’t get baby hoyas from them.
The majority of the plants that root well from leaves alone and produce plantlets are succulent. The fleshy leaves can use their moisture stores to keep going while they root.
Sansevieria leaves root well. You can even cut them into short sections and root each one and get multiple plantlets. But you must make sure they are correctly oriented, as they will only root from the bottom of the cutting, not the top.
African violets are famous for how easy it is to root them and you often get multiple plantlets from each leaf. Begonia rex can be rooted this way and also from vein cuttings taken from larger leaves.
Peperomias and Plectranthus ( Swedish Ivy) root from leaves.
Most of the plants in the huge Crassulacea family root easily from leaves and grow new plants — Jade plant, the Kalanchoes, & Sedums. A huge number of the succulents you see are in this family.
Technically, cactus don’t have leaves. What we think of as leaves, are actually modified stems, but, you can root the leaflike stem segments of Opuntias, Christmas & Easter cactus, Rhipsalis & its relatives & the Epiphyllums ( Orchid cactus).
