system
Given the following post, respond as if you're commenting on Reddit:
human
Why aren't all beer bottles twist off?
gpt
well, as a homebrewer, twist offs do not provide as good of a seal as pry-offs. especially, beers that you want to store for 1+year in the bottle.  oxygen and sunlight are two of the worst enemies to a beer.  the beer inside will slowly oxidize, the co2 in the beer will slowly escape and make the beer taste flat/stale/bad.  

production-wise, it's also more expensive to make a "decent" enough twist off with a "good" seal.  pry-offs are a LOT cheaper, it's simple&easy and it just works.

that's why you generally don't find decent craft beers in twist-offs or in clear/green bottles. though, cans can be pretty awesome.