I think this idea is objectively good, but practically hazardous. "Four nines" is a meme at this point, and it's a helpful one: a commonly understood gold standard. Few people know that translates to roughly 4 minutes and 19 seconds of downtime per month. Since service quality is degrading, I fear that changing the way we express those uptime might also unintentionally provide convenient cover to reset expectations, e.g. 10 minutes of downtime is the new norm for reliability. Or 30 minutes. I don't think we should yield the Overton Window, so to speak, to this.