And I'm pretty sure that random blue spot in Florida is Gainesville, home of University of Florida. There's certainly no major urban center there; the population just about doubles during football weekends. But the university serves as an anchor for startup activity.

As an inhabitant of Raleigh-Durham, I can testify that its "brain gain" goes beyond the three major universities in the area (NC State, UNC, and Duke). The "Research Triangle Park" which sits snugly on the border between Raleigh and Durham has offices for a great deal of major companies (typically R&D offices), but Raleigh, Durham, Chapel Hill, Cary, and Morrisville proper all have plenty of businesses to offer, too (e.g., Epic Games and SAS in Cary, RedHat in downtown Raleigh, Cognitect (of Clojure and Datomic fame) in Durham, etc.).

The culture in the area is great, and there's no better place for a craft beer enthusiast to live. Couple the excellent job market with the low cost of living, and it's a hell of a nice place to live. Of all the places I've lived, it's by far my favorite.

The places you mention are doing great which is fine but Pennsylvanian, Maryland, Ohio, Georgia & Virginia look at the map there are so many pink section. Also I have friends in this areas who ended up moving since their industry closed down.

Per the map,

VA drain: Lynchburg; gain: nearby Charlottesville, Roanoke, Richmond

MD drain: Cumberland; gain: nearby Morgantown (WV), greater DC

PA drain: York; gain: nearby metro Baltimore (MD), greater Philadelphia, State College

OH drain: Toledo, Lima, Mansfield; everywhere else neutral

GA drain: Valdosta, Macon; everywhere else neutral

VA and MD both have one small patch of pink amidst vast swaths of blue. They seem to be doing great.

> while a few smaller metros in Rust Belt states that are missing these amenities and are on the rural periphery are showing in 'brain drain'

I think that just looking at blobs of color is not particularly useful as some metro areas are much much larger than others.