Teleportation appears to require a certain power level and using the Never Never is easier, and there are different types of teleportation. Both Drakul and Namshiel used a line of sight teleportation, presumably the easiest as regards power expenditure, but Harry figured it out and ambushed Drakul, Ethnui did not.
I presume more elaborate teleportation is hazardous, it’s too easy to scramble oneself, materialise within something etc, and you only get one shot….unless you are immortal. Indeed immortality may be a necessity, if one can totally reform from atomisation isn’t that effectively teleportation?