That's because somalia doesn't properly follow the parliamentarian system.A president gets through so much hurdles such as campaigning, fundraising, bribing, making alliances to get elected only for him to be a ceremonial leader? In the countries you mentioned, the pm goes those hurdles that’s why the power in his hands. The PM is appointed by the president to execute the president’s ideas and goals
Somalia needs a powerful presidential system like France. French president is more powerful than the US president as he can declare war on his own, the US president needs congress for that.
The best way to have a balanced power is to make the president and parliament equal in power: the parliament needs a signature of the president to introduce a bill, and the president needs the parliament majority to execute his presidential orders. Just like in the US
Both the pre 1969 constitution and the current provisional one say that we are a parliamentary system.
Executive power is in the hands of the prime minister and his government which are voted by the parliament which is voted by the people.
The president's job should be to appoint the prime minister supported by the parliament and sign laws passed by the parliament.
Presidential systems like the US require a strong central government which we don't have. If we had only the president and no prime minister qabils would fight even more than now to get one of their own to become president, compromise would be very difficult