Why do we not say "tens of"?

We say 'hundreds of', 'thousands of', 'millions of', even 'tens of thousands of', but not 'tens of'. The usual expression is 'dozens of'. Does anyone know why?

Counting in 12s is a lot older than 1000s or millions. The traditional units based on 12 and 60 go back to the Babylonians, while 1000s mostly date back to the C18 metric system.

Indians also count in lakhs (100,000) and Crore (10,000,000)

We don't say tens of unless we are referring to larger numbers (tens of thousands, tens of millions, etc.). As pre-metric as it may be, here in the U.S. we say dozens for quantities between ~40 to ~100, which is approximately where tens would be appropriate if it were used.

That said, there is nothing wrong with referring to "tens of" something. It just sounds funny.

Update

For whoever downvoted me, here is a little perspective on the NGram issue brought up by onomatomaniak:

You can clearly see that when you compare dozens of to tens of for a couple of these identical constructions, the usage of dozens far outstrips tens. The only anomaly is when the noun modified is "miles," which is interesting but probably an outlier.

This illustrates the problem with Google NGrams. If you don't look at the orders of magnitude on the left, the "big jumps" can look very compelling. In fact, by comparison here the "tens of" lines, so compellingly vertical in the above graphs, vanish into flatlining insignificance.

I conclude from this graph that "tens of" is, as I say, falling out of usage, and is being supplanted by "dozens of."