This makes it hard to distinguish real differences from random variability. The human brain excels at finding patterns, even from random data. Statistical rigor prevents you from making this mistake. Statistical analyses are most useful when you are looking for differences that are small compared to experimental imprecision and biological variability. But in many fields, scientists care about small differences and are faced with large amounts of variability.
Statistical methods are necessary.
Statistical analyses are based on a simple model. There is a large population of data out there, and you have randomly sampled parts of it. You analyze your sample to make inferences about the population. The items you tested. The entire batch of items produced.