Some plants send up shoots from their roots and form big clumps of stalks and leaves. Some can grow leaves from pieces of root that have been torn up. Some plants grow from bulbs which can grow small new bulbs at the root level. Some plants can grow from cut off leaves or stems. Many of our house plants are shared this way.
Some plants even grow little plants on their leaves or root when a piece of stem is buried.
All these methods of reproduction work well. However, they do not make it possible for plants to move to new locations. They are vulnerable to everything that might destroy the parents. A viable community needs members with diverse strengths and vulnerabilities. In addition to reproducing asexually, most land plants also reproduce sexually.