Review is done before code gets into main, but that’s inefficient for most of the non-mission critical projects out there. A better approach is to optimistically merge most changes as soon as not-rocket-science allows it, and then later review the code in situ, in the main branch.

Assuming you have a project with continuous delivery, that is an absolute foot gun. Optimistically merge the change and then realize in situ that you forgot the WHERE part of your SQL command (or analog statement of the query builder)? No fucking thanks.