Why aren't lipids considered polymer?
a: basic unit isn't a monomer
follow up: is every other macro molecule (carbs, proteins, and nucleic acids) polyers

For a polymer to be considered a polymer it must be comprised of monomers like proteins and other macromolecules.

There are 20 different type of monomers present in proteins. Amino acids are in reality the monomers of proteins. Out of the 20 amino acids, only 9 are considered essential. The other 11 are of little use to the humans. The nine of the essential amino acids required by humans are Tryptophan, lysine, Histidine, Isoleucine, Valine, Threonine, Phenylalanine, Methionine and Leucine. The amino acids combine with one another to form different types of proteins. These proteins satisfy a number of our physical functional needs.

~potters6/te801/biology/biounits/respiration.htm

Ther are many reasons.. is it a multiple choice?