Having multiple reviewers is often <i>bad</i>. A diffusion of responsibility means no responsibility.<p>If you have three reviewers, no one feels personally responsible for checking it line by line and thinking about the code in depth. Instead a cursory glance seems acceptable, because, after all, other people are looking at it.
I think the next step from here is giving the ability to assign maintainers for certain sets of files (in this directory or matching a particular regex) and then when a pull request comes in, GH can looked at the changes, match the maintainers, and require all of them to sign off prior to allowing merging.
TLDR: github has a new feature that allows you to require X number of people to approve a PR before merging to a protected branch.<p>From the title, I initially thought this would be an article about <i>why</i> you should have multiple people reviewing PRs, which sounded ridiculous (obviously we don't all have the time/resources for that).