Having a head of state with ceremonial powers, of the kind found in most European countries, is harmless but a waste of time and money.
Having a head of state with real power of the kind favoured by, for example, just about every comic opera Latin America country has several disadvantages:
Disadvantage 1
There is a tendency for at least a third of the population to idolise the leader. Observe, for example, some of the old documentaries made during the aftermath of the assassination of that third rate show pony of a President, J. F. Kennedy. You can see numerous scenes of people who, after leaving memorial services to him that were held in churches throughout the land, disgracing themselves by bawling their little eyes out over the death of a perfect stranger who neither knew nor cared about them.
Disadvantage 2
A head of state with significant political power can destroy a country in a very short period of time, both economically and
politically. Once again, Latin America furnishes a number of excellent examples, including Uruguay and Argentina in the 1950’s, and Chile in the 1970’s. The danger of having an economically illiterate buffoon wreaking havoc on a country is considerably lessened (but not eliminated) in a system where there is a committee of politicians in charge, such as seen in parliamentary systems.
However, in the final analysis, both systems could best be described as elective dictatorships and neither system allows the people to be represented in any real sense.
Once the ritual of an election is out of the way, the persons elected, ie. those who falsely refer to themselves as “representatives” can do virtually as they please and can even indulge in abusing their power with relative impunity. The ability to be able to get away with abuses of power also applies to the civil servant class to a great extent.
Until such time as a latter day Solon establishes a system that would permit the people to be represented, it doesn’t really matter a great deal whether you have an elective dictatorship run by a head of state or by a committee. In neither case do the rulers need to take too much notice of the will of their subjects.
Incidentally, the claim that no one is above the law is believable only to those who look at the world through rose colored glasses.