Sharing and phishing are on two different axes. You can have shareable credentials that are phishing-resistant when used.
You can have hardware-backed SSH keys that are not cloneable. You would need the browser to prevent phishing while still using SSH agent as its underlying signature mechanism (implied by my "in a consumer package").
> ...sharing (and hence, phishing)
Sharing and phishing are on two different axes. You can have shareable credentials that are phishing-resistant when used.
You can have hardware-backed SSH keys that are not cloneable. You would need the browser to prevent phishing while still using SSH agent as its underlying signature mechanism (implied by my "in a consumer package").