As Harvard Professor Robert Putnam has pointed out: One of the effects of "increased diversity" is that there is a shift away from being a high-trust society. This causes, among other things, increased isolation and social disengagement.
No doubt this isn't the only cause of pubs / bars closing, but it is a real measurable effect.
My spitball opinion on that: we had diversity in America during the beginning of the industrial age that we heavily relied on for it's host of benefits, innovation primarily as well, but it didn't create the conflict (conflict theory terms) we see today because you were expected to integrate (conform) to be "American", which was a shared set of values and beliefs. America is still today one of the few geopolitical distinctions today that is solely demarcated as such by subscribing to a fundamental set of beliefs, rather than by blood as you have in most other countries in the world, especially in Europe. America is chiefly an idea, and by believing in that ideal, you gain the entire inheritance.
This is something that is continually being eroded unfortunately, especially as we continually descend into more and more hyphenated subgroups of Americans, rather than just focusing on what makes us simply Americans, but something we should still strive for.
(And I know you will get downvoted for posting about Robert Putnam research here because it appears to come off as a knock against diversity, even though Putnam himself said his research actually affirms the benefits of diversity)
Except your opinion does not actually follow from the facts.
African Americans weren’t just “hyphenated subgroups” earlier. They weren’t even allowed to be in the same places as white male americans. Similarly, Chinese Americans formthe most part lived a separate life, and Japanese Americans were considered so different they were placed in internment camps during WW2.
Even the Irish and Italians were treated differently when they arrived, and had entire sub cultures.
The idea that the US is more hyphenated today just doesn’t seem to follow from what was actually happening in the 20th century.
Early America was so hyphenated that people only occupied regions with people of the same original nationality. We still see places with lots of French street names, or a place with lots of German street names. To some degree this might have been self-selecting, but there are documented cases of people being denied mortgages in particular areas based on their ethnicity into the twentieth century.
We are in a place in American history where ethnicity has the least amount of impact on someone's life. It's illegal to discriminate on job applications, mortgage applications, or school applications based on ethnicity.
We have a lot further to go, and sometimes we take a step backwards. I think we'll continue to see an increase in diversity in all public spaces.
It's quite possible that the US is at an inflection point. Now those hyphenated groups are spread so thin that they lost all their meaning. Now you can't find comfort in sameness, because yes, you share some common history, but you are also very different in other ways.
And thus people can't seem to find their place, can't seem to find friends, and the default fallback of going back to your people is no more.
" In the short term, he writes, there are clearly challenges, but over the long haul, he argues that diversity has a range of benefits for a society, and that the fragmentation and distrust can be overcome. It’s not an easy process, but in the end it’s “well worth the effort.” Putnam cites the integration of institutions like the U.S. Army as proof that diversity can work."
The point about the army is a particularly interesting one because they certainly are experts in integration and conformity, which hits back to my point in my previous comment as well.
The army life is not a good example; it is an intense, catalytic experience that accelerates and exaggerates processes that may not even appear in the real life. For many people their army buddies are the people they trust because they trusted their life to them, nothing like this happens for regular people.
It's not just the military in wartime though. My father was in the US Army in the late 1950s after the Korean ceasefire was signed but when they were still drafting soldiers to be deployed there. It was the first time he had any major interaction with African-Americans as they were rare in the small Northern town he grew up in. Serving alongside them and realizing that they weren't much different from himself was a significant experience for him.
No doubt this isn't the only cause of pubs / bars closing, but it is a real measurable effect.