The process has changed since Lynch left (actually it changed ~the week he left Google). For promotions up to L5, the decision is made by people within your org

The process has changed since Lynch left (actually it changed ~the week he left Google). For promotions up to L5, the decision is made by people within your org, who should have context on whether you were working on the right things or not. By L6+ (even as an IC), part of your job is to make decisions that are good for the organization, so having to justify them is not unreasonable.