grammatical number - The omission of articles before the last two nouns in 'There is a missing bridge between business and technology'

I came across the following sentence in an article:

"There is a missing bridge between business and technology"

To the best of my understanding when a noun is used, it should have an article (a, an, the) before the noun. I found a Grammarly blog on the omission of articles, which suggested that certain nouns allow the direct use of singular nouns without an article. To me, the reason of why "business" and "technology" can be used is that they are under the special case of academic subjects. Is this correct?

Would it be correct too if I were to write it as:

"There is a missing bridge between businesses and technologies"

Another case I have in mind is this sentence:

"This allows the direct use of singular noun."

Is this correct? Or is an article ("a") needed before the word "singular"?

Another way to avoid the use of articles would be making the word to plural form (i.e. "nouns"). Is this correct?

It is my first post in StackExchange. Sorry in advance if I violate any rules or formats of posting. Thank you very much!