I can actually back this up, most job offers I get actually come from people I happened to work with that never get a public job listing and are only obtainable via being highly regarded by others. I was told that my friend in their department where the role opened up got an email about a senior position and to reply if they have a recommendation.

However, software development is funny in a way where you don't need a job in order to be successful. I've never worked at a company and I'm pretty up there on the ladder, but I am not quite sure what will happen in next few years when ever possible thing that can be made in software is already explored to the fullest especially with singular developers launching 3 to 7 projects a month.