W3C has repeatedly shot itself in the foot with sweeping mandates that major vendors oppose and which are then ignored; that's the reason we now have the separate WHATWG org and the reason W3C no longer leads much in terms of browser standards. Adding more mandates from tiny players (e.g. Brave) doesn't feel super useful, even if the group is supposedly focused on privacy — although the article even notes that at least part of the desire of the group was for "rivals to limit or handicap the ability of Google to compete against them."