I can provide some information on the topic.
Practically washing or rinsing dishes before placing them in the dishwasher is a matter of personal preference and depends on the dishwasher and its capabilities. Modern dishwashers are designed to handle food residue and can effectively clean dishes even without pre-rinsing. In fact, some manufacturers may even recommend scraping off excess food instead of pre-rinsing, as it helps the dishwasher's sensors and cleaning mechanisms function properly.
However, some people still prefer to rinse dishes before loading them into the dishwasher for various reasons. It can be a habit they developed over time, or they may have had experiences where their dishwasher didn't effectively remove certain types of food residue. Additionally, pre-rinsing can help prevent the growth of odors and bacteria if the dishwasher isn't run immediately after loading.
Ultimately, whether or not to pre-rinse dishes before using the dishwasher is a personal choice and can vary based on individual preferences, dishwasher performance, and the type of food residues involved.