The primary value I've seen across teams has been more on having shared team context across a codebase, if something goes bump in the night you've got a sense on how that part of the codebase works. It's also a great opportunity for other engineers to ask "why" and explain parts that aren't obvious or other context that's relevant. We'll find the occasional architectural mismatch(although we like to catch those much earlier in the design process) and certainly prevented bugs from shipping but if that's the primary focus I think a team is missing a lot of the value from regular code reviews.