The thriving cafe and food culture. It's the epicentre of this in the City. Leith Walk is full of businesses owned and staffed by 20 and 30somethings, the pubs are far more geared toward catering for foodies and socialising than just plain old drinking, which is pretty much all Leith socialising used to be about even up to and including back in the 2010s. Pavements are covered with young affluent people dining, drinking, socialising.
There is a significant population of foreign entrepreneurs living in the area, so aside from the usual Italian, Indian, Chinese cuisine which has long been a part of most Scots high streets, there are Hungarian, Greek, Georgian, Nigerian, Argentinian, Kurdish and a few others who I've no doubt forgotten, all seem to be fairing well. Surprisingly few Fish & Chip shops.
This is before you get to the Shore, which now has high-end boutique accommodation, high-end restaurants, quality pubs that mean it's not uncommon on a summer night to see literally hundreds of young people sitting by the water of Leith socialising. This is the area that until recently was awash with all the usual diaspora and detritus you'd associate with a busy port, i.e. less salubrious drinking dens, rampant violence, open prostitution with the girls standing by the side of the road looking worse for wear. The people who make up the local patrons now would not, and could not have set foot in the same place 25-30 years back. The Fort estate is gone, so there is no longer a housing scheme 2 minutes away which was a total no-go area for emergency services, instead, it's open and clean social-housing for families in an area thriving with the same type of businesses now seen on the Shore and Leith Walk.
Leith Links and Pilrig park are both now clean and busy any time the sun is out. You no longer need eyes in the back of your head just to sit and relax in the sun, or constantly comb the ground for fear of accidently sitting on a dirty needle. The scrap yard in Salamander Street is going, the associated noise will be a thing of the past, the contamination of the ground is being dealt with, newbuild flats all around, so the approach to the port itself no longer looks like a scene from a post-apocalyptic movie. Seafield prom is being regenerated, the car dealerships going, more flats and businesses in their place along with public gardens and recreational areas.
So yes, there are undoubtedly some "overpriced" flats available in Leith, but that's a symptom of the fact Leith is not what it once was and there are actually people who do aspire to come and live here now. The property price rises reflect the changes.