Ask HN: Inbound marketing with just LinkedIn and GitHub? (freelancer)

Freelancers, have you done any marketing just through these two channels? And what has worked for you?

I've been freelancing on and off for about 4 years now. Usually it's more famine than feast, but I had a consistent freelance job that lasted about 7 months and just ended at the end of February.

Now I'm trying to find more work. In the past, I tended to go on Reddit or Slack channels related to my programming field. But I need to build a bigger pipeline of clients and referrals.

Also have been browsing the Who's Hiring/Freelancer monthly threads, although none of the interviews from my responses have converted into offers so far.

I rarely meet my clients in person, nor do I network. But I've heard of people who don't do this anyways but leverage inbound marketing in other ways. I want to know if this is possible with just LinkedIn and my Github account. But should I be carving out a niche first? I guess web development is still too broad to start contacting people on LinkedIn.