Leaving bacon out at room temperature for 10 hours is not ideal and can increase the risk of bacterial growth, particularly if the room temperature was warm. Perishable foods like bacon should generally not be left out at room temperature for more than 2 hours.
The fact that it doesn't smell funny is not a reliable indicator of safety, as some harmful bacteria might not produce noticeable odors or off-flavors. Bacteria can still be present, even if the bacon appears and smells fine.
To ensure food safety and reduce the risk of foodborne illnesses, it's best to follow the principle of "When in doubt, throw it out." Consuming bacon that has been left out for an extended period could potentially lead to food poisoning or other health issues.
If you're uncertain about the bacon's safety, it's better to err on the side of caution and discard it. It's not worth taking the risk with potentially spoiled food. In the future, try to refrigerate perishable items promptly after use to maintain their freshness and safety.