Anecdotally, as someone who has been involved in hiring and (sort of) cares about side projects, it's not actually the technical implementation I care about, that's true. It's about the applicant signalling "I care about this stuff". But it's far from the only indicator and shouldn't be given too much weight. I'd gladly hire someone who had no side projects but passed our technical test/interview and soft skills interview.

As for why I don't take Github profiles too seriously, we had plenty of applicants who did have projects on their Github profiles who tripped all over themselves on our simple coding test. Maybe we would have found out something similar by digging into their commit history, but that would be an even greater time investment than the hiring process already was.