I ask whiteboard coding questions not because I care if the applicant can do some trivial task, but basically to gauge familiarity. Someone who writes code in a language every day for their current job should not have any trouble expressing a simple algorithm on a whiteboard. It's a screening question, and for someone who knows what they're doing, it shouldn't take more than 5-10 minutes. Once that's out of the way, I talk about their body of work, problems they've solved, etc.

The problem is there are a lot of people who didn't do the work but were around for it. They went to all the meetings, they can tell the war stories, they know the jargon, but they just didn't write the actual code.

As for your question about github profile, the problem is that you can't really tell how much work someone did themselves. I'm sure you wouldn't misrepresent your work on github, but people do. People outright lie. They are probably not even being malicious about it, they just don't have a good sense of their own coding ability and feel like if they just post something that they "could have" written.

One applicant who I really liked really struggled writing code on a whiteboard. He described some projects that he had built himself for university, and that sounded really interesting and reasonably complicated. So I took a look through those, hoping that he was just having a bad whiteboard day. But unfortunately it just confirmed, he was smart, creative but just didn't have a lot of practice writing programs. The code was a mess, it did bizarre and roundabout extra steps to do simple things, and from the timestamps, represented months of work for things that should have taken days. I did admire that he was tenacious and didn't give up, and in the end he build something cool but just didn't have enough practice to write production code without supervision. I would have wanted to hire him for an internship, but that wasn't was we were looking for.