The pile is very different now than it was 2 weeks ago.
In what sense?
Again, we have so few facts. And going into each argument seems crude at this point imo.
But...
There was a significant fire that burned for days, 2 weeks ago.
There were still voids 2 weeks ago. Voids are good for possible survivors, bad for shifts. Now there are no voids, meaning less chance of shift.
There was a partially standing building that could come down at any time 2 weeks ago. Additionally that building blocked a massive part of the site for access.
There was a hope to find survivors 2 weeks ago, you can't use machinery to scoop up a pile of concrete if you are hoping to find people inside of it.
It was MUCH bigger 2 weeks ago.
Those come to mind, I'm sure experts can list many more differences.