It is important to optimize your database for a number of reasons. A bloated database can slow down the site and the backend, or even crash it. Sometimes a loss of data can occur.
If the database is large, it doesn’t necessarily mean that it is not optimized and vice versa. If you are selling WooCommerce products, your database will surely grow in time. However, redundant data will pile up after a while, so it is important to clean your WordPress database periodically.