[kach22i]

cinderblocks = FAIL

And they are not called cinderblocks, they are called Concrete Blocks. Cinderblocks was a term used generations ago for a much weaker product no longer made.

Concrete blocks as retaining wall = Fail

Much engineering (and expense) to make it anything else.

Concrete blocks lack the mass to hold back the earth, and require filling with grout and rebar used with massive footings and must be weeped. Of all structures prone to failure for structural engineers and architects retaining walls top the list. A lot of engineers and architects will not even touch them and leave the liability to the landscape installers using pre-engineered products.