What’s the problem with applying the VCG mechanism to a trading problem that involves both buyers and sellers, each with private information?

What's an example of real-world mechanism design problem you could imagine wanting to solve?

[Learning to mitigate AI collusion] How does the Stackelberg game framework apply to the dynamics between online platforms and sellers?

(Optional) [Learning to mitigate AI collusion] In what ways can regulators keep up with the rapidly evolving AI technologies used in pricing strategies?