I find most anything that comes from china is no good. Low quality steel, recycled non virgin steel, alloys full of crap just to add to the weight and volume so less steel is used and so on. And then they will over heat treat it to compensate for low quality and turn it into even worse brittle garbage.
The steel of yesteryear is gone... new age crap is just that.
Bosch used to be the cream of the crop, I remember drilling into rebar and reinforced concrete for 10-15mins at a time non stop, the bit would turn red hot... but the carbine tip never changed shape or lost sharpness.
Last year I melted a whole box of Chinese Bosch bits in just a few hours... they looked like mushrooms
Name brands don't mean anything anymore.. can't rely on the name to hold up what once it meant. Irvin, milwaukee, dewalt, diablo, rigid, etc... most of the stuff from the big box stores anyways.
Still some quality stuff out there, but for the most part it's the small scale production lines, built in the states or EU... and usually the crazy prices reflect that. Unless you're making money with those tools, it's almost not worth getting it unfortunately.