"That's how great arguments work: you agree with every step (and after a while you start believing things you didn't originally)."

Also how great propaganda works.

If you are going to describe a "great argument" I think you need to put more emphasis on it being tied to the truth rather than being agreeable. I would say truly great arguments tend not to be agreeable, b/c the real world is so complex that descriptions without lots of nuance and caveats are pretty much always wrong. Whereas simplicity is highly appealing and has a low cognitive processing cost.