Often it is, and often it isn't. Sometimes the same manufacturing facility will have different quality standards for different buyers, and the distributors run by people who own yachts will not accept the same level of defects as the others. Name brands have to stand by their products and provide warranties, because their name is supposed to mean something. Random shell companies that exist only to sell knock-off products don't care if your charger stops working in 6 months.

I'm not suggesting you have to buy name brand shit, because in practice those companies have demonstrated that they aren't as committed to quality as one would hope. But if you're buying an $80 Samsung product for $25 from Symsnug Ltd, you have a much higher chance of throwing it away.

It’s often things made with exactly the same machines and materials as all the others on the market

It's worth noting that for items where quality can vary factories will typically bin the output products. Better quality into the bin going to this expensive brand, worst quality goes straight to Temu, lowest quality that meets Walmart's standards goes in this bin, etc.

For anything where the silicon quality really matters you want to bear this in mind. TVs, and LEDs are the biggest ones where the silicon part makes light for you to look at and the quality can make a big difference

Edit to add: cheap no name chargers are a great way to spend several hundred dollars replacing your phone because you wanted to save $5 on a charger/cable. Personally I don't gamble with phone chargers, and you can get a good, high speed USB-PD charger for $20 now so it's really not worth the risk. Heck I got my 3 port name brand GaN USB-PD charger for $35 so the bottom is really not worth racing for now