What a hot take! If you're in an organization where leadership 'points the finger' at McKinsey to cast blame for an unpopular decision, imagine what sorts of decisions they would have made without the consultants!
Consultants are hired to improve decision quality. They do that through a combination of analysis, experience, and industry connections. The work product is rarely 'powerpoints'. The work product is the actual work, which entails people doing research, making decisions, executing on them, and measuring results.
At any rate, I don't disagree with you that consultants aren't going anywhere. This post is an ad for an immature AI service that makes a bunch of claims about how they've solved for hallucinations and knowledge cutoffs in order to take down McKinsey. If they had solves for those problems, they'd be wasting their effort building a replacement for consulting firms.