They sell fairly space-efficient, expensive products or services. Generally speaking, the higher you push rent per square foot, the fewer types of businesses you can operate, because people and products take up space and have throughput limits. Nail and beauty services can get spendy fast.
The US has something similar going on with medical and dental offices for the same reasons.
The other US phenomenon is mega-chains which can operate at much narrower margins (or even negative margins in some marquee locations).