I have seen no credible explanation on how current or proposed technology can possibly achieve AGI.

If you want to hand-wave that away by stating that any company with technology capable of achieving AGI would guard it as the most valuable trade secret in history, then fine. Even if we assume that AGI-capable technology exists in secret somewhere, I've seen no credible explanation from any organization on how they plan to control an AGI and reliably convince it to produce useful work (rather than the AGI just turning into a real-life SHODAN). An uncontrollable AGI would be, at best, functionally useless.

AGI is --- and for the foreseeable future, will continue to be --- science fiction.