[Daedren]

Reminds me of Telegram that forces you to pay premium to login to a new device depending on the country. Login, not registration. This is all due to the cost of SMSes of course.

You can bypass this if you have a passkey, but phone and password isn't enough. No idea why they opted to do that, it's not like passkeys are indicative of any device binding.

[sumanep]

sms are free, at least rcs

[jeroenhd]

RCS is not SMS. RCS does have a fallback to SMS in some rare inter-carrier cases, but it won't fall back if you're stuck on 2G or anything.

SMS also isn't free. Many contracts contain "free" texting, but that's just SMS being packaged into the subscription price.

Carriers charge each other for (excess) SMS exchanges, so SMS simply cannot be entirely free.