If I say "A greater amount of cookies is better," the subject "A greater amount" is clearly singular.
One of the definitions of "more" is "a greater amount of," so it seems logical that replacing that exact clause to make the sentence "More cookies is better" should be valid and should have the same meaning. Additionally, "cookies" could be implied by context, or omitted to generalize the statement, forming the sentence "More is better," which some quick googling confirms is definitely valid.
However, I'm fairly sure that "more cookies" would usually or always be considered a plural noun, which would require that the substitution with "more" has to be accompanied with changing the verb, making the sentence "More cookies are better."
That sentence seems wrong to me, though, because it's not the cookies that are better, but the amount of them, and "the amount" is clearly still singular.
Can this focus on the quantity make "more [countable plural]s" be singular?
The question "Two are better than one" or "Two is better than one"? is similar to this, but I believe the presence of a plural countable noun in the subject clause ("more cookies") makes this question substantially different. I tried googling before I posted this question, and I did not find that question. Even if I had found it, I would have been very uncertain about whether its answer applies to my variation. Reading that question and its answer would not have resolved my issue for me.
