I second Stefan’s and others’ want for the quote-all button to at least be possible to enable by specific site-admin configuration. It is rather inconvenient, borderline troublesome, to mark text for quoting while on a normal phone with touch-screen.
Typical use-case with quote-all button is to quote-all and then edit/remove as needed. A much simpler WoW (unless the original text was looong).
Please consider adding it back as config possibility.