Besides a better look, protecting the above water surface of the hull with a good quality wax also prevents the gelcoat from aging. This oxidizing process is due to the UV impact to the gelcoat, making it more “open” for dirt to stick better and making it look dull. Before our current boat we had a Bavaria 300, which took me approximately 4 hours in total to polish. Previously I used 3M marine wax, which lasted for the season, final years I switched to Riwax hard wax with very good results. Upon the sale I even got compliments from the surveyor for the good appearance of the hull (after 30 years!).
So a good quality polish is really worth the money…