I have the same issue. On android tablet Brave it will sometimes appear if I refresh the page after loading - but there needs to be a toggle or menu button.
Feature is called Reader Mode in Brave Browser iOS, and there is an icon at the right end of the URL address field.
Not in December 2022 there is not. No toggle icon for reader-view/simplified view at all. And the problem noted by @holsen remains true.
It seemes developers are not reading the various threads where this much desired feature is mentioned.