Sentence Structure

I'm looking at Amazon’s Antitrust Paradox by Lina Khan and I come across this sentence:

"Second, because online platforms serve as critical intermediaries, integrating across business lines positions these platforms to control the essential infrastructure on which their rivals depend."

and I can't make sense of it, especially this phrase:

"integrating across business lines positions these platforms to control the essential infrastructure"

Eventually I realize that "integrating across business lines" is a noun. The sentence might have more easily made sense if those words were hyphenated, like this:

"Second, because online platforms serve as critical intermediaries, integrating-across-business-lines positions these platforms to control the essential infrastructure on which their rivals depend."

Once I finally deciphered it, I can no longer see what was so confusing about it.