Still rough thoughts, but...

You can imagine a city that has high quality mining, ore refining, blacksmithing, swordsmithing, leather work, and thriving markets.

The quality of these institutions all reinforce the other...

It's not just the infrastructure of ore --> refining --> smithing --> sales, it's also even basic taken-for-granted elements like knowing which smiths work on reliable timetables, whose ore is consistently made well, and the basic personalities of the various proprietors.

Heck, even knowing the correct addresses and how to navigate the city streets is valuable.

All of these things don't appear on a balance sheet, but there's something to them. The infrastructure isn't solely the physical infrastructure - it's not just the smiths, anvils, tools, transport, whatever. It's also the relationships between those.

Nobody can claim those as their own. They're not assets in the conventional sense of the word. But intuitively, we understand that the relationships between these elements contributes to thriving industries.

I think we can call this "cultural infrastructure" - less about the physical stuff, and more about the relationships and interplay between the different people working on the physical stuff.