Incidentally, I read a post today which swore that the only way to get hired is NOT to rely on network. Because hiring managers receive so many applications if you don't get your app in the first 24 hours it's guaranteed to be rejected.
I think the network thing works only for smaller companies.
Hey - you're looking for a job? Come work here PLEASE!! As a company you can get folks who'd otherwise go elsewhere as well this way because process can be shorter - you've already worked with them maybe in other contexts etc.
One issue now with hiring is just the crap you have to wade through. When hiring was local and/or in office interviews it was one thing - but now it's honestly wild. The number of responses is INSANE. I used to make a point to read every resume (just a glance at least) - that's impossible now (it's slow anyways on a lot of sites to flip through resumes).
Outsourcing is definitely up as well since overall remote is up and has made that easier.
Then you've got scammers - we've definitely contracted with one person, and when talking with them later its a different person entirely. Ie, email grammar falls into trash.
In my experience, in bigger companies hiring managers seem to dislike this kind of "nepotism". The best they do normally these days is to give you the hr/recruitment email to send your application to. This is just some real-life experience based on recent job hunting.
Openings/needs can be shared and relayed through networks before being listed publicly. You can also made yourself know as a potential hire before the need arises or before it is fully validated/budgeted and getter recontacted on Day 1.