>they can just use glass

Does anyone even recycle glass anymore? I know it used to be a thing but I think fresh plastic bottles probably cost less than even the collection and sorting costs for glass. I haven't seen any recycler ask for glass in ages.

>Companies need to stop externalizing their costs into environmental problems and telling people it's their problem for buying it.

They are just giving people what they want at a price they can pay. If you really want to minimize waste, the way to go is probably for people to make their own soda at home using flavor extracts. It's easy and probably less polluting to do this than anything else. But when you're not at home, you have to have drinks ready-made.