The point is very simple - there was once a day when we had considerably more control over the way we use computers and the networks that connect them. That is slowly being taken away, piece by piece, until the only path to use them is to 'consent' to whatever demands the corporations put up. Not that this doesn't exist already, but today will seem like the wild west in comparison to what's coming.
"Big tech is coercive and evil" isn't a new view, but "passkeys are one of their tools and not just some agnostic technology-first nerd solution" is still not widely known.