These days I assume most parts are offshore sourced. I assume OEM parts are too. There are good offshore and poor offshore parts. You guess which is which. One local shop will not install non OEM parts....too many comebacks. I usually take my chances because my labor is free although it depends on the size of the job.
Generally I agree, you don't know where it's coming from, BUT, I know OEM's have that pesky warranty to worry about, so it's in their best interest to make sure their parts aren't crap.
I picked up the Ford parts. "Majority of componants sourced in USA" is on each package except the water pump which was made in Mexico. Mexico I can handle. When I see the shitty Made In China labels (with what seems like the same damn font on everything made in China, no matter who is selling it), my BS flag is raised.