Originally git repos use to signal for passionate developers, the kind of people that you couldn't stop from coding. Before the 2008 boom there were far less people actively interested in software and the best were the ones that just loved it. The rest where people working in corporate farms that still hadn't got laid off from the dotcom burst.

Then the startup boom started again and a new round of devs came into the profession looking to make money and needed to prove themselves. They heard "good devs have great github profiles!" so they started creating github profiles and flooding them with code to get hired.

Now we're in the new wave of cargo cult white boarding/code challenges. You may hate them but at least the early FAANG challenges were interesting and challenging. But since every company has to have them you have devs that couldn't pass a google white board challenge trying to create their own version... which usually means they are poorly thought out.

Funnily enough, a GitHub-to-resume tool recently hit the front page[0], but yes, that opinion seems to be in decline.

[0]: https://news.ycombinator.com/item?id=20995056