Since they are the same products made in the same factories in many cases, what’s the diff?
Well, for one thing, that's not necessarily true in all case, or even..., in most cases.
And for another reason... when it does come from the same manufacturer, you may not realize that the way a manufacturer can save on the cost of his name-brand stuff, is by rejecting certain parts of the raw products that they buy for their name-brand stuff -- and turning those "rejects" into the off-brand label. They don't have to throw it away (and they wouldn't), they don't have to resell the raw products to another outfit (which wouldn't get them enough money back) and so they simply make an "off-brand" from their reject stuff for the name-brand stuff.
It's the same manufacturer, using the same equipment (different "runs" though), with the same packaging (different labeling, though) and with "reject raw products".
Heck! That manufacturer can save a lot of money that way, for their name-brand stuff... LOL...
“Many cases” is not the same or as much as “all cases” or even “most cases”, which is why I purposely chose that phrase. Thanks for reading.