The industry mix of Memphis (i.e., logistics and transportation) is not really conducive to hosting a 21st century knowledge economy. The city is becoming less important as a transit hub as MS River and transcontinental rail traffic continue their terminal declines and there isn't really a top-tier research university nearby from which local industries/start-ups can draw reliable STEM talent. Memphis is also almost two-thirds Black, which is another major reason tech bros aren't very interested in investing or living there lol
That being said, comparing Memphis and Nashville proper is very apples-and-oranges. Nashville is a combined city-county; if you include all of Shelby County in with Memphis it still bests Nashville's population by more than 200k (combined Memphis-Shelby still has almost flat growth, 0.2% between 2010 and 2020.)
Do you mean passenger rail? Freight rail is still going very strong and probably has yet to peak.
