Your question is Layer 2 vs Layer 3 Scaling. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
What are the common challenges when scaling Layer 2 versus Layer 3 in modern data centers?
Discuss the control-plane, data-plane, failure-domain, convergence, and operational trade-offs. Explain how technologies such as VXLAN, EVPN, ECMP, MLAG, and BGP address specific limitations.
Keep the answer focused on modern leaf-spine data center networks and distinguish inherent scaling challenges from problems introduced by a particular implementation.