wow, great that Apple will support RCS eventually! even if just as a second class citizen, like SMS.

the webapp definitely does need the phone in the loop at all times. if you put your phone into airplane mode and then try to send a message, it complains and fails.

RCS may be internet instead of cell, but it still evidently depends on both your carrier and your specific device, so it may not be easy to support without a phone.

(there’s also RCS’s Universal Profile feature, which evidently includes many of the “advanced” chat features. so, yeah, complicated.)