The following is a sentence from an article I was reading:
But the problem is that, after the Trump Administration wasted the time that was available to prepare for the pandemic’s spread, by instituting widespread testing and creating additional hospital facilities, today’s Draconian measures are both necessary and probably insufficient.
My question is why the author put a comma before “by”. Is it used here to avoid confusion because with a comma, it means that “instituting widespread testing and creating additional hospital facilities” are how the time was being wasted, but without a comma, they could be interpreted as the ways to “prepare for the pandemic’s spread”? Or is it used just to put a pause in the parenthetical element, because otherwise it would be too long?
Thanks for any help you can offer.