Who is more better in their respective own domains among work done in last 1520 years?
Terrance Tao vs Acemoglu

Acemoglu can write papers on pure math. Tao can't write papers on pure econ theory
Yes, mathematicians cannot write papers on econ since they cannot bear to write nonrigorous BS that will be wrong in 50 years. And, you certainly don't know what pure math is.
They most certainly can bear this and frequently do.