"[..]The biggest chunk of those infrastructure costs, fully $6 million annually, goes to telecom firms to pay for the SMS text messages Signal uses to send registration codes to verify new Signal accounts’ phone numbers."

This is the PoW part to protect from fake accounts I suppose. Can Nostr fix this in the future?

nostr:note13z2l4d45mu2qhh9txhaamfhykxdx5vnzayyaauhdvefhhkq89tfsynved8