I agree with that assessment, and would avoid a FSBO. The people who go this route don’t have an impartial person to assist with the negotiation, and in RE deals, emotions get in the way at least once. The first emotion to get in the way is the seller’s ego, and he thinks his house is worth 20% more than it really is, because he feels he is special and thus his house is special, and someone will come along who sees the real value of this unique home and will pay much more than it is worth. Without a realtor to bring in some reality, the first mistake is made: a high price which prevents any showings. Without showings: no offers.
The other emotions that get in the way would be negotiation to fix things, compromises on dates and so on.
I like talking with the seller directly, but I have my doubts as to their ability to make a clean deal on their own home.