In the last few years the pendulum has been swinging back from inhouse engine to Unreal Engine. There are a couple of holdouts, but my guess is that the majority of AAA games currently released are back on UE - at least it feels that way ;)

And Unity always ruled supreme for AA and mobile games.

There are many studios with their own engines that rival or exceed UE5 - which seems overhyped, because at this point they caught up with graphics fidelity without terrible performance that dread a lot of UE5 titles.

Recent notable example is Crimson Desert, they spent years building their own engine for this game and IMO they raised the bar when it comes to creating a huge realistic world.

Others that come to my mind are Decima and RE Engine.

The IW Engine is basically UE5 at this point (for your CoD example.) The fact that it's a proprietary fork is fairly irrelevant to it still being assembly-line work.

Most massive studios have their own which they use across a bunch of titles