I have never seen any kind of technical documentation published in any other format than PDF that is comfortable for reading and searching, even when that is done on a mobile phone.
I do not want a document that changes appearance depending on the device used for reading or depending on its temporary state, like window size. I want a document whose layout has been well conceived by its author and which is fixed, regardless of what I happen to use for reading it.
When I happen to read it on a smaller screen or window, except for trivial text-only documents, I do not want changes in layout, but I only want a smart reader, with comfortable means for fast zoom and pan, and which does not have stupid behaviors (like some Android readers), for instance where scrolling vertically (including Page Up/Page Down) also moves the document horizontally (preventing the easy reading of a column of text).
The traditional recommendations for the maximum width of a text column are good enough, if observed, to ensure comfortable reading even on a mobile phone. Only when the author breaks the traditional typographic rules by making extra-wide columns, the reading on a mobile phone becomes inconvenient.