You are right - a lot of those plants are just babies that will outgrow their small space. Its hard to find a truly small plant that stays a small plant. Even your Grapto is going to grow out of its space.
I have orchids that are full grown at just 1 or 2 inches. Also miniature violets stay under 2 or 3 inches. Some cactus never grow beyond a couple inches.
I'm sure others can add to this list.