Wait, do you claim that underwater cities can not keep with technological specialization because the needed technologies aren’t obvious enough? If you want to submit specialization so a species has nothing better to do, they’ll just need supply of essential things to live which is achieved by farming items. If you want specialization I imagine you give everyone easy access to essentials so they won’t have to work hard for it themselves, and then you’d just need some sort of idea passing system (or school) so people gain knowledge through others. This causes interest in some of the most random things and eventually some individual will gain interest on it. Governments and human-like political forms usually don’t pick up on short term benefits except to boast, but anyone else could. After the individual gains certain material and sufficient amount of labour their project will be done. Just to be clear, the steam engine and metal forgery didn’t start specialization, they’ve only amplified it by spreading ideas. The real starter was agriculture which allowed people to do other things than look for food (they can settle down and think). Also, you hinge more into the industrialization of farming. The industrialization factor does not deal with steam engines at all, that was just am amplifier for production. You also seem to not account the fact that industrial production refers more on the term of trading items, goods, and services and not what fancy tech you can use to do so. There are still technologies and concepts that have specialized outside of such a range of metals.