I guess you could include Ibadan as well, but the city is economically underdeveloped.
The only reason people are migrating to Lagos in such large numbers is for economic reasons. Lagos is the financial capital of Nigeria, and it's where people move to for job prospects and upward mobility. If smaller towns across Nigeria were developing at an equal rate, there would be no need to move a city as densely populated as Lagos. Development needs to be ubiquitous throughout the country, and for that to happen, the economy needs to be diversified and state and local corruption needs to be redressed. They have some ambitious projects like Eko Atlantic, but that still is only catering to the upper-middle class and neglecting the lower and middle-income earners. Lagos also has a problem with shanty towns that it has to deal with. Where are these populations going to go once serious urban renewal projects begin?
I agree, with the majority of the population being well below the standard of living financially, the extravagant cities and communities so to speak will only widen the inequality gap. I agree that raising and building the average home for the majority would do the country unprecedented rewards.
Labor in Nigeria at least in the north is extremely cheap. Dudes literally learn the trade of building homes. If they (being the corrupt government) invested in the common man and conman woman and their trade we would see and exponential amount of growth for Nigeria.
I am from one of the three largest families in Kano. My mother is related to the king. There's plenty of money to go around its just funneled to the few. My aunt studied in London and now has opened up we own dentistry. Fully furnished equipment, plaques all over the wall and patients for days! Many uncles and aunts who have their PhDs form European universities and have their own business or are professors. Not everyone has that type of money and education to build off of and I admit it's a blessing to come from wealth. But I also have family that farm, and are very profitable over there as well
There is opportunity, oil will be exasperated and that could be the demise of Nigeria if it doesn't fine alternative measures and practices