I have been to 20 UNESCO World Heritage Sites in my lifetime... 5 in the USA, and 15 in Europe.

Europe has the most cultural ones, due to the long history and historic events. But the USA seems to have most of the sites that refer to either natural wonders, native American sites, and just a few historic sites [Statue of Liberty, Independence Hall, Alamo, select homes of Frank Lloyd Wright].

I had always wondered why Detroit during the era of Transportation & Industry [1900-1930] wasn't added to the USA list, since so few buildings are on the list in the USA. With the finishing restoration of Michigan Central Station, Detroit really does have some of the most amazing buildings of the early 20th Century. After all, after NYC and Chicago, Detroit was the fastest growing city in the USA in the early 20th Century.

And as is the case with so many surviving architectural treasures worldwide... most of the treasures of Detroit survived because the city went stagnant during a long period, and there was no need to tear them down for something newer.

The Art Deco skyscrapers, downtown movie palaces, some of the historic factories in Milwaukee Junction, the treasures in the Cultural Center, the MCS, etc., would make Detroit a great tourist attraction that most folks here [and elsewhere] just don't know about, unless the come here and are shown what we have.

Now having Detroit as a UNESCO site doesn't have as much ummph as it would in Europe, where people search them out as travel destinations... but being on the list would surely benefit the city as a travel and tourism destination... and help negate many folks perception of us as some of the more unflattering labels that 50 years of news reports have pinned upon us.

I checked the list of UNESCO World Heritage Sites... and the USA is really low on the proverbial totem pole historically and culturally...
https://whc.unesco.org/en/list/

And getting added to the list does require a series of steps... none of which really puts Detroit out of reach for such a designation...
https://whc.unesco.org/en/criteria/

We are getting more Great Lakes tours coming thru, that see a lot of what Detroit has to offer. Maybe Detroit could be ahead of the curve vs. other American cities that have qualifications for being added to the site list.

It sure couldn't hurt!