Small anecdote on the mobile/robotics part, two years ago I was tasked with a small research sensor/timelapse platform. I reached out for the Pi Zero 2 W, the new Pi camera, and the largest USB battery I could buy. Perhaps I had unrealistic expectations, but I was surprised how much power it draws, even at idle. The napkin math said about 6 days (0.5 W idle, 2 W loaded), in reality it was only 1-2 days.
In comparison, my older laptop idles at around 5 W, even with multiple applications open. Similar experience more recently when looking at setting up a small home lab, the new Pi 5 seems to idle at around 5 W. A friend told me he has an Intel-based mini PC that draws less power. I'm tempted to try re-purposing an old phone, that should in theory do better.