Using bright screens after sunset hurts sleep. You should set your screen to as low a brightness as you can after dusk. But some screens can become dimmer than others.
So I measured the minimum brightness of all the screens I have at night:
iPhone XS: 1 lux
iPhone 11 Pro: 1 lux
Google Pixel XL 1: 3 lux
iPad Air 2: 3 lux
iPad Pro (2015): 3 lux
iMac (27-inch, Late 2015): 11 lux
MacBook Air: 15 lux
LG Gram 17 (2019): 110 lux
These were at minimum brightness level for each screen, measured on a fully white screen (Google.com), with blue light reduction off. Measurements were made using this app running on the iPhone 11 Pro. This app isn’t accurate, but since all we’re interested here is the relative brightness, it should be good enough. In any case, it matches what my eye sees.
Notice how bad the otherwise excellent LG Gram laptop is. So my first takeaway is to not use that after dark. Second, no computer is as good as an iPad, so I’ll use only iPads after dark. Which also has an added advantage in that I’ll end up doing light content consumption instead of serious work, relaxing my mind for bed.