Do paperweights really need battery life?

It's all relative. To me, saying 5% better (reddit test) doesn't sound that good. But it's still an hour in an absolute terms, and an hour for me is a significant amount of time, no matter if the base is 10, 20 or 50. Still an hour of content more.

For the gaming I'm not so surprised. Whenever the chip is more efficient, they keep the TDP envelope mostly the same, so that the power available to user is bigger (like in case of gaming). The efficiency will be the most visible in low-mid demanding tasks (or even standby time would be an interesting parameter to compare).

I'm not disputing whether Apple exaggerated or not, it was a marketing presentation, I'm always a bit more reserved (you know, superlatives everywhere, graph axes, blank comparisons, multigenerational comparison, selective comparisions etc...)