This is true of a lot of product types, but there is often a QC process that happens for the "premier" name brand that they were manufactured for. And these "duplicates" are frequently the irregulars that didn't make the cut.

In the case of knives, they may be perfectly fine. Or QC's spot testing of that batch may have revealed defects in the metal, and a small number of them may shatter unexpectedly.

This is why I'm fine buying some categories of items from AliExpress et al., and not others.

What kind of knives are we talking about?

I have a Leatherman Skeletool and a Buck 110 knife, and both are such high quality for what feels like a reasonable price (especially considering the warranty), I just can't imagine chinesium beating it. Yes, I know Nextool exists, but I would just be too wary that there's gonna be a batch where the factory or QC skimped on quality. Snapping a multi-tool or even worse a knife can have serious consequences.

It’s more clones of 200-400-800 dollar stuff for 40-100 dollars. They’re in many cases definitely made by a different place than the oem because they based their design on public stuff online image and specs wise then made their own tweeks. Usually slightly different geometry, often one of d2, 8cr, 9cr, vg10, 154cm or m390, with first 5 usually being honest labels. (The vendors say mark foo when it’s just visual blade print label. ). There’s def some instances where the clones also actually have design tweeks that make them competitive or better than the originals in fit and finish.

Afiact, the Main good vendors are green thorn, lemifshe and jufule currently. But if you ask the vendors detailed questions before spending money they seem pretty honest.

As for a blade steel breaking, that should be less likely with Chinese blade heat treats since they all tends to err on the side of undershooting hardness and cap out at 60hrc. So in many cases way less brittle than a western heat treat if it’s the same steel