Re-using glass containers is actually an extremely low chance of contamination. We have had easy glass sterilization techniques for a long time (most dishwashers have a sanitization cycle). Further, your shelf life won’t be significantly reduced, unless you just don’t clean your containers.

The underlying argument you were responding to wasn’t really greenhouse gas focused. The discussion was mostly about plastic waste in the oceans and our environment. While it is possible the greenhouse gas budget is better with plastic, this doesn’t address the problem of accumulating forever waste within our environment.