Dynalist is an outliner. Obsidian is what used to be called a wiki. (Many current ‘enterprise’ wikis are not really wikis in the original sense). Wikis are about the (back)links between pages as much the the pages themselves. This is largely also true of Roam, RemNote, HyperNotes & Legend , but they are more wiki outliner hybrids. The new buzzword for wiki is “networked thought”. Personally I find Dynalist - as the by far the best - online outline a far more unique and compelling proposition. Wikis are dime a dozen, but I have said all this before in an earlier incarnation of this thread
Note: I love wikis and Obsidian looks like a very good one, but so are many others.