New too. Quite a few times I was reading long topics on meta and by reflex presses the reading mode button, then realized that it didn’t work on this site.
Let’s say, I have five topics that I’m interested in reading. I don’t want to read them one by one or I’ll forget about them, or their order will shift. I don’t want to bookmark them because it is a hassle.
In this very common case, I’ll just load each topic in a separate tab. Clean and tidy. Except that it uses up a lot of resources on mobile. The perfect solution is to press reading mode in each and turn them into text, as after reading I won’t need it to go back. I’ll just close.