Note that I wrote "most countries other than the US".
Your first reference seems to be US only; the second one lists around 2-10 cent per message to most non-US destinations.
Since this is based on what phone networks charge these service providers and other networks for inbound SMS, anything much cheaper than that is usually using unreliable SIM farms or even more dubious means of message delivery (like hijacked Android smartphones on unlimited messaging plans used without the owner's explicit consent).
Viewed globally, cheap and reliable outbound SMS are a US-specific anomaly.
