Because there ARE new files added The display is not live, it takes time to update. It's expensive on resources to continuously count all of the files on the servers so we only do it periodically.

So really the question should be: why is the archive size not increasing when files are added?

I was wondering if it was live, and it makes sense for it to not be live. But then we could reach 5TB and not know about it for a few weeks..

The display does update several times daily and it is automatic. This is why you see it drop when the 2nd server goes offline.

Thats right, it does drop sometimes, so we would only be late by a few hours for the party, and we would anyway even if the counter was live.