The latter could be accomplished by shipping a privacy-championing browser that enables those behavior by default (Brave? Apple?).

You're saying the low levels of adoption of such technologies are indicative of users' subpar technical skills, but maybe it's just general apathy and disinterest? E.g., how many public protests and calls to action have we seen after Snowden revelations?

FWIW, the former is already prevalent among younger generations, with Instagram for their "public" life and f-Insta for everything private.