Am old enough that this was status quo for part of my career, and have also been in some groups that did this as a rejection of modern code review techniques.

There are pros & cons to both sides. As you point out it's quite expensive in terms of time to do the in person style. Getting several people together is a big hassle. I've found that the code reviews themselves, and what people get out of them, are wildly different though. In person code reviews have been much more holistic in my experience, sometimes bordering on bigger picture planning. And much better as a learning tool for other people involved. Whereas the diff style online code review tends to be more focused on the immediate concerns.

There's not a right or wrong answer between those tradeoffs, but people need to realize they're not the same thing.

I would guess that 3 part code review would actually be most effective. Likely even save on costs. First part is walkthrough on call, next independent review and comments. Then per need an other call over fixes or discussion.

Probably spend more time on it, but would share the understanding and alignment.

Pair programming? That is realtime code review by another human

And yet... is it? Realtime means real discussion, and opportunity to align ever so slightly on a common standard (which we should write down!), and an opportunity to share tacit knowledge.

It also increases the coverage area of code that each developer is at least somewhat familiar with.

On a side note, I would love if the default was for these code reviews to be recorded. That way 2 years later when I am asked to modify some module that no one has touched in that span, I could at least watch the code review and gleem something about how/why this was architect-ed the way it was.

Fagan inspection has entered the room