what is the stronger point of stats and planars that is better the dynamics?
For stats it is the membrane weight and drive across the entire membrane. The disadvantage is output level. The driver surface area is big which has advantages and disadvantages. On can play with shape to change modal behavior.
Difficult to drive in the sense that it requires a bias voltage (or electret charge) and high voltage on the plates. Requires mains voltage or converters.
Mechanical tension is a must and 'sticking' to one stator is a potential problem.
For planar magnetics (incl. ortho dynamics) it is the max. SPL and linearity and the driver size. The latter can be a blessing and downside (frequency dependent).
One can use less tuning methods and is difficult to get a bass boost in a passive way.
The magnets obstruct the sound waves more so than the stator of electrostatic planars which has an influence on mid to high frequencies.
Easier to drive than electrostatic but in general inefficient compared to dynamic drivers especially when high SPL is needed with good linearity.
Heavy in weight due to the magnets compared to other drivers.
Can handle a lot of power.
Needs closed front volume to work properly.
Dynamics can have a much higher efficiency but at the expense of max. undistorted SPL. Can be used directly from low power sources.
Much more ways to 'shape' the sound signature of the driver/headphone.
Cheaper to make. Lighter in weight. Membrane size and shape can be used to control modal issues.
Linearity (max SPL without distortion) can be much worse than planar. For lower to normal SPL this usually is not an issue.
BA drivers are smaller and can be easily used close to the ear canal. These drivers too have stronger and weaker points and quite different from dynamic drivers. Easier to make custom molds for due to size.