I do wonder if part of the issue though is that we have thousands of these 'great' features, so discovery is poor because people can't possibly know about them all. 'great' features lost in a sea of other 'great' features.
anyway, at least a few dozen other people didn't know about this feature, so i guess the post was helpful anyway. for the record, just now i tried and couldn't find any reference to these modes in the first 2 queries i thought of, so it's not trivial to find that it already exists (although i do not use google or chatgpt). i just assumed that if the feature existed i would have heard about it before, so i wrote a blog post, and it was fun.
to your point about discoverability, i think that's true, and there's no comprehensive user manual for android, which would be the normal way one would discover features in a device. hm, that's another feature i'd like in my phone: a built-in digital technical manual, like the safety & regulatory manual.