This is beneficial to the manipulators for various reasons, be they financial or political.
It’s as old as time. They just happen to be on the Internet now and we’ve atomized society to the point where they’re super common.
Most everyone is an incel until they’re not. After all - there’s a point where you want sex and aren’t getting it. Thus, an incel.
Online, in incel echo chambers, such voices of reason and wisdom are expelled. The incels then spiral into unchallenged worldviews that alienate them from the general public, isolating them from women and everybody else even more than they were before.
Nowadays, you're constantly pushed all kinds of random shit. The usual incel rhetoric that I see is - there's not many women to talk to. Which is mostly attributed to the decline of social spaces due to again - whole atomized society stuff and late stage capitalism, yadda yadda. (If you haven't heard about it yet - just read some robert putnam)