Comparison of alternating current and direct current in transmission lines

I wonder why most of the transmission lines are used ALTERNATING CURRENT not
DIRECT CURRENT. List below are the following reasons.

Advantages of direct current transmission lines
The advantage of DC transmission lines are only two conductors to be used
and there is no problem of system instability, in a DC line has less corona loss
and reduced interference with communitation circuits, since the same value of
voltage therefore the insulating materials on DC lines experience less
stress compared to AC transmission lines, in a DC transmission lines also no skin
effect on conductors, therefore the entire cross-section of conductor is
usually utilized thereby affecting saving in materials. also same load and
sending end voltage, and voltage drop in DC is less than AC transmission lines and
you no problem of inductance, capacitance and phase displacement which is common
in AC transmission lines.

Disadvantages of direct current transmission lines
The disadvantage of DC you cannot anymore step-up or
step down you voltages in equipment like transformer.
And the generation of power at high DC voltages is difficult due
to communication problems and cannot be usefully utilised at consumer load.

Advantages of alternating current transmission lines
On AC transmission lines has less power losses in high voltage and
there is no commutation problem. possible for step up or step down
voltage.The power can be generated to a high voltage.

Disadvantage of alternating current transmission lines
There is increased of effective resistance due to skin effect and more copper
is required. The construction of AC transmission lines in very much
complicated and costly. There is problems of inductances and capacitances because
it exist in transmission lines.