This is not always the case. For example, I work in a midsized consulting firm at a fairly senior level. While I have a line manager, he’s only there to give me corporate news and policy. He not only doesn’t tell me what to do, he often doesn’t know what I’m doing.
What happens is there are a pool of account executives who I have grown to know over the years. We talk regularly, and if there is something I could work on (pre-sales or a project), we talk and figure if I’m a good fit and have bandwidth. Unless I have almost no work I can be choosy about what to work on. Yes, clients and the account guys can mold my deliverables, but I have a lot of sway in that as well.
This also lets me figure out my own hours, within constraints if engagements of course. Since I have kids in school, this gives me great flexibility to schedule work around family, instead of vice-versus.
So while what the author describes as regular jobs may be common, it is not the only model.