I am not exactly following the part about when “other companies…” and what the implication is.
I can say that a part of the delay is likely attributable to how the CID (caller-ID) is setup. In NA, the CID information is delivered between the first and second ring. The device will then deliver the call once this is received.
Additionally, depending on the service used to call the device, it is not uncommon in many cases that the carrier will provide the initial ring while delivering the call to the destination, even though the call may still be in the process of progressing to the destination, so that the caller has feedback rather than dead air.