Having worked in startups for most my career, and now recently joining a BigTechCo, I think some of the cross-talk comes from the commingling of concerns within

Having worked in startups for most my career, and now recently joining a BigTechCo, I think some of the cross-talk comes from the commingling of concerns within a PR. PRs are used to review architecture, enforce security/code-conventions/style, check for logic bugs, catch potential conflicts with other efforts, and validate the logic of a feature. In BigTechCo you have more coordination problems, so you want to merge code to trunk as soon as possible to prevent integration risks. But that means you drive discussion of the architecture and features to other venues than than the code review. Code review becomes more of a "will this break things" check, and enabling a feature-flag is more the review stage for the feature itself.