It makes sense to me that there is nothing in Skyrim that compares to the Imperial City. There really shouldn't be.
That would only be a valid argument if any of the last three TES games were actually to scale. They aren't. There's no reason to limit the size of your new cities because you don't want to overshadow one ostensibly huge city you created half a decade ago. Especially when you consider the size of Morrowind's cities.
But if you have a bar where the Thieves Guild hang out, a bar where the Commona Tong hang out (or whatever the Nordic equivalent would be), a place for the Fighters and Mages, etc. ... suddenly you have a place that feels a lot bigger, even if essentially al you have are several different types of inn.
This.
Redundancy is important.Take Balmora, where you have three general goods shops (an outfitter, a pawnbroker, and a trader), five bars/taverns (Lucky Lockup, the Razor Hole, Eight Plates, Council Club, Southwall Cornerclub), an armorer, a tailor, and an alchemy shop with guild equivalents of each located within the local branch of the fighters and mages guilds, a bookseller, and the local temple with various merchants and spell sellers inside. This isn't even getting into the large number of residences and manors that already tend to dwarf most Skyrim cities.
This idea that there should never be more than one instance of any given service in any given place is boring. Every town just feels like another extension of the game (instead of an extension of the world), giving the player only what
they need. Instead, towns should be designed with believability and logic in mind. Skyrim lacks this philosophy.