Furthermore, rings can be used to create energy blasts of various types. The construct creation ability wouldn’t allow a Lantern to create functional kryptonite, but one could use the energy projection function to emit kryptonite radiation, which has been done in the comics before.

Ok, thank you I keep seeing wildly different views of how Green Lantern would do in a fight against Superman, and I wasn't sure what to make of it.

They wouldn't fight. They're friends.

But if Green Lantern ate Superman's cake? Then superman be mad

He'll just catch Luthor. I heard he took 40 cakes. That's as many as four tens. And that's terrible.

Little known fact, Green Lantern power rings have the uncanny ability to create Green Eggs and Ham.

In the SA the ring could do more than just create hard light constructs, but we’ll conveniently forget about that.

Writers in the Silver Age often conveniently forgot what powers could and could not do.

What about the Golden Age or Silver Age GL? I don't remember specific examples, but I remember reading they sometimes materialized things out of thin air, or transmuting elements into something different. I might be wrong and just remembering a completely different thing, but if they are capable of that, they could be capable of creating Kryptonite if they new its chemical components, right?

^^ I swear those last two comments weren't there by the time I was writing the above.