I find what I do on the device matters more than anything. Like arguing on reddit/twitter/here is the dumbest thing to do in general, but even dumber right before bed.

Reading a book or something doesn’t seem to be much different for me than reading something online.

There’s an accessibility setting in iOS to dim the screen when you triple click the home button as well. I use it along with night mode but most of the benefit seems to be from making it so uncomfortable to read my iPad that put it down and go back to sleep.