So many people here don’t really know what they’re talking about. Chip companies can’t cut corners on stability because of the amount of money that goes into everything around the chips is huge. If you think of a PC motherboard and you look at how many components are on that board now, imagine if one of the company’s cheaped out on a chip and didn’t bother testing it before sending it out and the only time they found out it was bad was when they finished making a board. The cost of finding, repairing and replacing those components far exceeds the pennies that they save by cheaping out.

The real answer is that their customers are a user of the chips and the cost of a bad part is massively more expensive than a tiny savings in manufacturing the chip.

The only place they cheap out on parts is in things that are standalone and dirt cheap such as an RFID chip. I’ve seen those get manufactured without test and only at the very end after they’ve been assembled to their antenna they then test and reject the ones that fail. They get away with it there only because the cost of the chip and antenna are so cheap.

Imagine Apple putting a sub-tier component in their phone and having to recall 10% of their phones because of it. It’s unheard of. The people who buy the chips are usually companies that use them and they have a very low threshold for bad components. While it’s true, some parts are binned for performance, they are never binned for quality.

Note - I’ve been involved in the test of semiconductors for the past 20+ years making load boards (package test) and probe cards (Wafer test) for many different IC manufacturers.