It has been a while (I think ever since Safari introduced Reader Mode), and I do almost all my reading on websites in Reader Mode. For some websites, I have set to “Use Reader Mode when Available,” such as that of paulgraham.com, daringfireball.net, and quite a few others with horrible Typography.
> I don't understand though why reader mode is not always available. The text is there.
Mostly because we don't have any standard markup to say "this is the content". Which means reader mode has to guess which tags contain the content, and this whole thing boils down to a pair of regexps[1]