I think it is a niche brand, but its ubiquity definitely depends on the location— I lived in Hong Kong and in Latin America for a good while and would see the gancini belts and shoes everywhere.
I do not mean to sound rude, but even the 7/11 clerks, who could be undercover billionaires or could have saved their yearly income for those things, but I doubt it (worked there when I was 17ish). In other words, it was kind of the Neverfull effect, where you see a million on your way from home to the corner store, but nine hundred thousand out of those are fake.
In the rest of the places I have been to, I have seen very few accessories (a Sofia, maybe a couple of Vara pumps) and incredibly, I have spotted more RTW (not tons of it, though). The demographic is very specific. I wouldn’t say it’s necessarily older people (even though my paternal grandma and my mom do own their fair share of shoes, bags, RTW and a couple of sunglasses, which are amazing BTW), but I wouldn’t say it’s teenagers either. Again, this is in the rest of the world, according to my experience.
I own and enjoy some of their shoes and RTW, maybe as an acquired taste and have also bought different pieces as gifts, but I definitely wouldn’t run into the store and empty my bank account, despite their efforts in the latest years to appeal to younger clients and their great customer service. HTH.