It depends on a lot of things. People like to think it's a wonder material but if you pay attention it's typically only used for very specific applications.
First the weave pattern impacts stiffness a lot, one of the beautiful things about CF is you can make it incredibly stiff in one direction but flexible in another for example as used in formula 1 suspension parts. However, I've noticed a couple of the CF handle knives without full liners exhibit more flex in the handle perpendicular to the blade than their counterparts, and you can easily deflect the handle scales just by squeezing them. If you don't pry with it, which you shouldn't be doing it's not an issue. I'd imagine that flex could make a liner/frame lock collapse earlier, but again only after you do something you shouldn't.
The other thing CF is very poor at is abrasion/impact resistance. Once you damage the weave/laminate it tends to peel exposing the fiber weave, and you do not want CF in your skin, it makes fiberglass look hand lotion. You crash a CF road/mountain bike frame where it takes any significant abrasion and it's ruined. In a knife handle that's not likely to happen, especially since most high $ knives don't see hard use, and people typically are not beating on the handles. Depending on the epoxy used it may or may not be resistant to chemicals, UV etc.
It's an okay material, amazing in the right application, but unless it's peel-ply it's too slippery and worthless for anything but looking pretty in a knife handle, and I doubt most of the CF used in knife handles would take anywhere near the same impact/abrasion abuse as Micarta or G10 without damage.
Most industries go through a phase where they try to use CF for everything as a "wonder material" and over time learn where it works well and where it doesn't. I suspect the knife industry will learn this as well.
This makes a lot of sense, thanks!
All quality motorbikes helmets are made from fiber glass, not CF, CF it's not impact resistant.
This is exactly why I asked.
Just because a material is good for some things, does not mean it is good for all.