There are several benefits of cleaning/washing your pool filter instead of replacing it, including:

Cost savings: One of the primary benefits of washing your pool filter instead of replacing it is cost savings. Over time, replacing a pool filter can be expensive, especially if it is done frequently. Regular cleaning and maintenance of the filter can help to extend its lifespan and reduce the need for frequent replacements.
Improved performance: Washing your pool filter can help to improve its performance by removing dirt, debris, and other contaminants that can accumulate over time. This can help to ensure that the filter is working at optimal levels, which can improve the overall cleanliness of the pool.
Environmental benefits: Regularly washing your pool filter can help to reduce waste and protect the environment. Replacing a pool filter often means disposing of the old filter, which can contribute to landfill waste. By washing and maintaining the filter, you can help to reduce waste and be more environmentally conscious.
Convenience: Washing your pool filter is often more convenient than replacing it. Replacing a filter can be time-consuming and require professional installation, while washing a filter can often be done easily by the pool owner.
Long-term benefits: By regularly washing and maintaining your pool filter, you can help to ensure that it lasts longer and performs better over time. This can help to reduce the need for frequent replacements and improve the overall health and cleanliness of your pool.