Umm. It's very hard to fake actual contributes to actual OSS projects. You might be able to fill your GH account with crap that might fool some people into thinking you have a "profile" but when you say you are "Committer to X" or "Contributed X feature to Y" then that isn't fakable and is the only stuff I look for.
So yeah, it might not be useful for recruiters/sources that don't understand the technical side deep enough to evaluate but it 100% sure be good signal for an interviewer if they know the fields and projects in question you are hiring for (they probably should...).
So yeah, it might not be useful for recruiters/sources that don't understand the technical side deep enough to evaluate but it 100% sure be good signal for an interviewer if they know the fields and projects in question you are hiring for (they probably should...).