They are not a carrier period! They don't sell transit. A Tier 1 carrier does settlement-free peering. They are a CDN. And no the most certainly do not have a "global carrier-level backbone." Argot or whatever they are calling their product is not an actual backbone with dedicated fiber, submarine cable etc. There would be no reason for them to invest in fiber and lightwave gear as they are en edge network full stop. Your comment shows a lack of understanding of how the internet actually works.