Soak dishes? At what point it can become dangerous to health. At least an hour in standing water is too long for bacteria to spread.
Plates with leftover food after you have eaten meat, fish or seafood are particularly dangerous. If the dishwasher considers the pre-cleaned dishes to be clean, it washes them with less cleaning power. Due to the increased water consumption, you are putting additional strain on the environment. If you have a dishwasher, you should generally not wash dishes by hand, but rather use it.