I don't disagree.. but I stopped really using oauth when realizing that I could lose access to all those services if the whim of an algorithm closes my (oauth) account.
Right, but using OAuth doesn't mean using Google, Microsoft or Facebook for everything. It's common cause it's convenient, but has issues like you say.
Someone running a Discourse forum could very well run say Ory[1] to have their own OAuth2 authentication service, if they wanted. Hopefully things like this will get a bit tighter integrated than it currently is.
