Just stay booted and use a lower power microcontroller … 105mA … that’s not the right order of magnitude
But of course the article is good enough because it's interesting, even if it's not the right tool for the job.
I am (sort of) in a same boat as the author. I have a silly little project that takes pictures that I PoC/mock-ed with RPi Zero. It does use battery, but I am not overly concerned with battery life - however boot time is killer. It takes loooong time to boot and be ready. However I wrote all the code in an afternoon and it just worked.
I could use a higher level language (Python) to clue in all the C libraries that are used to talk with my camera, screen, and wifi stack.
I know that I could achieve way better battery life and boot time by switching to ESP32, which is why I ordered one the day of after I got my PoC working. The parts have sat 9 months in my projects bin. I did write the basics of getting the image bytes off of the camera, but after that I couldn't find the motivation to continue. I already have a working version of the thing I wanted to make. It does everything I want already. Why spend bunch of time figuring out the way more esoteric libraries and actually try to implement everything (again) in C just to get a bit better battery life and boot time?
Of course in a "production" system it would be very weird and suboptimal to continue using RPi after this point, but for a small one off or even low run project any extra development effort feels like a waste.
I should dig up my project and see if I could flip some config bits and get the boot time lower, I'd be extremely happy with anything sub 10 seconds and then I could completely burry the EPS32 idea as redundant.