When you know no better....

Depends what we're talking about.
Many quality name brand cranks n rods are indeed from China and then either machined here or checked, fixed or sent back. Rockers...the needle roller kind ..they're a one season on average deal..but you gotta know that to begin with I guess.
Summit timing chains, half the camshafts, some or a lot of the aluminum small block heads are Chinese -seepmasters and some other reboxes. The valves...in most of the off the shelf cheap heads and possibly edelcrock, Chinese too.
I've got Chinese a.m magnums and Chinese stainless valves and who knows where comp makes their valve springs..locks n the rest. I've got h beams probably Chinese and finished by ohio crankshaft, the nodular crank. Idk...
Proform...garbage, wrong shafts and the needle rockers destroy them..while having their life span.

If it's not a 'if'... but when.. that's called a lifespan. Know it.
As for parts stores... duralast sucks, every other part is a warranty 2 times at least.
Mail order, lack of info and you get some wacked ****. I bought ball joints that intended the knuckles drilled and taped to fit the smaller shank. Ridiculous.
Experience is key, talk to people and sometimes be the guinea pig... take the leap and do some trials with the parts.
Get what you pay for? sometimes.. other times you simply pay what it's worth ... meanwhile others pay double 'for a warm feeling'