Why does shark vacuums still pick up a dust bunny after sweeping the carpet with another sweeper?

I was sweeping my low pile carpet with one vacuum cleaner, and went over it with a shark. The shark vacuum cleaner bagless container was empty but contained a dust bunny a size of a golf ball. Does that mean my first vacuum cleaner has poor suction?
Answers

Anonymous

Maybe it was user error. Maybe you just missed it. Hand vacuums aren't too bad. I use one to pick up crumbs and dirt from my shoes, also the bed if it gets gritty.

clayton

Agitation was superior.