It always depends on the exact position, but if I had to pick just one, then I'd say "controlling space." If you have a nice space advantage that is supported (not just pawns advanced too far which can become targets), then that means the opponent has less space to work with by definition. This makes it usually tricky for the opponent to defend everything in a cramped setting or mobilize piece to where they need to go - hence I think this may be more important than your own defense in many cases because you'll have the attacking initiative and they won't have time to counterattack you if you have the initiative.
Also, by "defending" I am referring to pieces/pawns defending each other so nothing is hanging. Keeping material form blatantly hanging is something beginners deal with but obviously hanging pieces is something all levels of chess play should avoid. My argument is that the pieces (even if hanging at the moment) can only be taken one at a time and if your attack is strong enough or swift enough with the initiative, then they won't be able to take your forces in time.
For examples: check many games from Mikhail Tal; he clearly understood the power of the initiative and the fact that hanging pieces can only be captured one at a time lol.
Generally speaking.