if there is an OSS project that you have your eye on, you can easily get noticed by engaging with them and starting to fix/address small issues or convenience features. I know a handful of people who got hired this way.

I think this is very unreliable channel, but something worth to try in parallel.

To be specific, I am not looking for a job atm, but current approach seems broken, and wondering why companies don't like to use more efficient ways to hire.