Cork is degradable, recyclable, and does a very good job at a specific thing. It's the bark of a tree which regenerates every few years, so its harvest leaves the tree unharmed.
Maybe it makes sense for Australia not to use it but I don't see why it should be replaced everywhere.
The only real issue with screw caps is the wine makers inexperience with using them can put too much sulphite in the wine, but this is a problem that has mostly gone away over time.
You know, I like wine. I've drunk plenty of wine in my time. I've read folks write things like '1 bottle out of 12 [is cork-tainted].' And yet I've never, ever had a taint bottle of wine. Is it just that I'm drinking younger wines?
FWIW, I love real corks and I hate how wine and liquor bottles have been replacing them with lifeless plastic.
You can really notice cork taint when you are drinking the same wine/ vintage regularly. You will open a bottle and it just tastes "flat" compared to what you are expecting. Open another bottle of the same wine and it tastes fine. This is cork taint.