According to a poll by GE Appliances in 2018, they found that 50% of people will use their bath towels at least 5 times before laundering and 14% of people will use their towels more than 8 times before washing it.
People tend to believe that being just out of the shower means they are clean, thus they are using a clean towel on their clean body so how could it possibly get dirty.
Even though you have just stepped out of the shower and cleaned your body with soap, each time you use a towel on your face, body, hands, etc. you are transferring skin bacteria or any other germs you may be carrying onto that towel. This is true even though you have likely soaped down your body and feel as though everything is clean.
Hand towels are also a major breeding ground for bacteria. Your hands transfer microbes to the towels every time you touch them. Even after soaping them up, you still have microbes present on your hands that transfer to your clean towels, which are no longer clean.