Let’s start with the obvious: what happens when that person dies or gets bored with it? Do they decide who the next in the monarchy will be? What is the process?
What if the BDFL decides they don’t like you or think that you are “shaming” someone according to their interpretation? The “dictator” (that’s their own word for themselves) gets to make all the final decisions. For software this makes a ton of sense, but for a community where open dialog is the goal?
Perhaps that is the issue, openness and dialog. Perhaps it isn’t always good to have such openness.
For example, I have final say in what gets said in my Twitch channel and Discord. I moderate what I don’t approve. That’s perfect acceptable in such circumstances. In fact, if I don’t do so I can get banned from Twitch without it even being me that violated the terms of service. I’m held accountable by Twitch for the communications from others.
It’s a complicated question, with no easy answer.
Personally, I think the solution is decentralizing the forum itself. Get rid of the entire ability to gate keep that got us into this problem in the first place. Create technologies that allow individuals to manage their own allow and follow lists and let them make recommendations to others, but don’t force one “BDFL”’s opinions and agendas on every single person in that community. It is the opposite of democratization of knowledge and information to do so.