I think so. Plastic needs tons of processing to go from raw material to plastic. You're basically (in terms of glass) cutting out all the energy spent mining for sand and (in terms of plastic) cutting out all the energy spent searching for crude/natural gas/coal, extracting crude, taking it to be refined, taking it somewhere else to be turned into a polymer, having the plastic pellets moved to where they're melted into the product, and then having them melted from plastic pellets to whatever needs made.

In the cases where plastic is a byproduct of gasoline production (which I think exists?)... Maybe it's not worse in a sense (?) but we really shouldn't be producing gasoline at the rates we are now.

At the very least, glass is a much more renewable resource (at least pending advancements in polymer manufacturing). It also doesn't leech into things like plastic does WRT food contamination.

Not to mention pollution wise glass is far better (there's no great pacific garbage patch made of glass).