Let us say you import old factories, down to the last screw, from a place that is upgrading like India or Indonesia. You begin producing steel, clothing, appliances etc.. of 1960s quality. You then need to sell those 1960s products to remain viable.
Problem #1: Why would Somali consumers buy 1960s products when they can import 2020s products that are probably cheaper?
Solution: you ban the importation of products that compete with those that are locally produced. You are doing import substitution.
Problem #2: Now that you have locked out foreign competitors, the already deeply backward firms no longer have a need to become more efficient/viable. They just sell their shitty products and pocket the money.
Solution: You tell banks to stop lending to the least efficient firms and levy heavy taxes on them. You pick winners and losers. Which firms get loans and favorable taxation, and which ones donāt.
Problem #3: Now that you are in the business of picking winners and losers, how do you prevent state capture(corruption) now that firms know their fate is in the hands of government bureaucrats?
It goes on and on like this. It is a thorny issue that is very hard to get right. Import Substitution Industrialization, or ISI, implemented in the 60s destroyed many African economies in the 70s
Your best bet is to jump straight ahead to the frontier by inviting firms from advanced economies to manufacture in your country. This is what China did and it is what Vietnam is trying to do now.