Both London and Chicago:
Urbanized area population of ~9 million people, which makes sense because the Midwest and the UK both have ~ 70 million people
Objectively peaked in global importance a century ago and are obviously in decline
Greasy unhealthy food
Old money aristocracy that is hard for outsiders to break into that fund all the high culture and arts
Big social emphasis on pub culture and heavy drinking and after hours underground electronic music
More of a loose archipelago of *many* insular neighborhoods than a unified citywide vibe
Culture heavily shaped by extensive post war immigration from eastern and southern Europe
Economy that became increasingly reliant in the 90’s on financial sectors that entered structural decline in the 2010’s
Two world class research universities ~1-2 hours away from the city center that are about two hours away from each other
Lots of other parallels too!