Hear me out: stats should be on the decibel scale, referenced to a standard human
For those unfamiliar, decibels are a base 10 logarithmic scale referenced to some baseline, typically used in situations where there's a wide range of numbers being discussed in the same context.
So on the dBsh (standard human) scale, an average baseline human would have a stat of 0, while a stat of 10 would correspond to someone 10x stronger, and a stat of 20 would correspond to someone 100x stronger. A stat of -10 would be someone 1/10th as strong as a standard human.
This doesn't solve the problem of convincingly writing a world where some people are 10,000 stronger or smarter or faster than others, but it makes it easier to discuss the numbers! Looking at you, Zac.