It depends on what you mean.
People know I can sharpen knives, so it's not uncommon for folks to bring their knives by for "service". I clean them up, do whatever I can to make them work better with the tools & resources I have (lubricate pivots, tighten screws/pivots, adjust pocket clips that are too tight or loose, etc.) and then sharpen them. I can tell which ones are garbage and which ones are quality by the time I hand them back to the owner.
But (assuming they're not dangerous or so shoddy that they can't hold an edge at all or will break almost immediately), all of them serve their intended purpose and even the relatively cheap ones do so quite well.
Does that mean there's no benefit in buying higher quality? No, it doesn't mean that at all. Higher quality does buy you tangible performance differences. Edges that are less likely to chip and that won't wear away as rapidly due to use and repeated sharpenings. Blade geometries that are functional and durable. Pivots that operate smoothly and don't loosen up rapidly. Locks that continue to work properly as the knife accumulates wear. Handle materials that continue to look and perform well even after lots of wear and use. Clips that won't break or bend and aren't so tight that they tear up clothing or so loose that you lose the knife. Designs that are well thought out and are therefore easier/safer/more pleasant to use and that work better.
As with anything, the returns diminish as the price goes up. A $65 knife is probably a tremendous practical improvement over a $15 knife, but going up another $50 to a $135 knife won't provide nearly the same benefit. And going from a $135 knife to a $300 knife may barely provide any practical benefits at all.
Of course, it's not always about practical benefits. There are other valid reasons people buy $500 knives, and how well they stand up to hard use or perform in a rope cutting test may not enter into those reasons at all.
