That is not unique to the Dyson brand.
The Toshiba bagless cleaners work well in my experience.
I started out by vacuuming the floors with my existing machine, and used tried the dyson afterwards. The amount of stuff it sucked up was very surprising.
Sure the dysons are a lot more expensive than the generic machines, but I have to say that I loved mine. It's only because I live abroad now, and I don't have carpets that I've not looked into getting another.
Other brands started to sell bagless vacuums only after Dyson first success. For other brands, bags was as profitable market.