The first safety warning assures the user that "plugin security is important to [Obsidian]". That Obsidian plugins undergo initial code review by Obsidian themselves. That "many" plugins are open source and that Obsidian has a "large community of developers who watch out for each other". (At this point I'm not sure how this screen even qualifies as a safety warning. Seems more like a billboard for enabling plugins?)
Given that vaults are just Markdown documents, and plugins are so safe (or so Obsidian seems to claim), why should a person feel at all concerned clicking yes to these prompts? Is it still a social engineering attack when the app appears to encourage you along the way? Are these even safety warnings, or just (vaguely encouraging) confirmation dialogs?
I don't see how Obsidian should come off as completely blameless here. They've always tacitly encouraged this wild west plugin ecosystem, because it's an obvious generator of value. They don't get to absolve themselves of any responsibility by pointing at safety warnings, when those "safety warnings" spend (far!) more time explaining why the user might want to click "yes" than "no".
To be clear, I like and use (and pay for!) Obsidian. But the design of Obsidian plugins was clearly broken from the beginning, and the official messaging around them has always been more encouraging than wary. This sort of event is an absolutely inevitable consequence of those decisions.