And they don't have any mechanism to capture the generated energy and convert it to electricity.
I assume the cost is “good enough”.
https://www.newscientist.com/article/dn13545-nanomaterial-tu...
The neutrons from fusion reactos are far more powerful, so they punch much more easily through materials you put in the way. Also, the ICF reactor has many moving parts (the pellet needs to be put in a very precise position for the lasers to shoot), so transferring heat from it is not nearly as easy as a much simpler fission reactor (which is mostly just a hunk of uranium which stays hot, and all the complexity comes out of being able to prevent the uranium from getting too hot).