I find this kind of advice underspecified. The people struggling the most to find work are juniors: what projects are big enough that the applicant would a) know and care about them and b) get a benefit out of the network but also c) have fruit low enough for a solo junior to reach?

I tried this way-back-when and ended up submitting fixes to projects that were open source but had no real path to accepting patches from people outside the cathedral.