The answer to 'why is my patio erosion' is that patio erosion is a common issue caused by factors like water runoff, soil type, and weather. Symptoms include uneven surfaces, exposed soil, and drainage problems. Solutions can involve improving drainage, adding gravel or pavers, and stabilizing the soil with plants or retaining walls.
If the erosion is minor, you may be able to address it with DIY methods like adding topsoil, reseeding grass, or installing erosion control fabric. However, for more severe or complex issues, it's best to call in a professional landscaper who can properly assess the cause and implement a long-term solution.