Why don't we have grand-uncles?

Is there any reason why we traditionally go from uncle/aunt to great uncle/aunt, instead of following the same levels we use for parents, grandparents, great grandparents etc.? Were the terms grand-aunt and grand-uncle ever widely used in any region or time period?

Genealogists prefer “grand-aunt” and “grand-uncle” over the “great-” versions, because they parallel “grandmother” and “grandmother”, who are of the same generation.

While not dealing with the OP I would like it to be known that my great-niece told me (after taking her for a ride on my Harley) that I was, “Teenage cool.”
And I do know for a fact that I am indeed, “One Great Uncle.”

What Walloon said. It’s just problematic to get non-genealogists to use the right lingo.