Those manufacturing videos are of someone making the exact same thing over and over. Months and years of testing go into ensuring that there is no change in the system, and continuous monitoring is put in place so that if any changes slip in, it can be undone. The design is set in stone, as it should be, and variations are bugs. There are months to years of cheap prototypes, iteration, design changes, pipeline tuning, and verification to ensure that nothing will need to change for the next million items.

If you want a software analogy to those devices getting churned off the assembly lines, it's the TCP streams coming out of your network card, with crazy checksums punching out bad packets.

We're orders of magnitude better at reliability with code, but we're regressing on that metric rather quickly. And the comment above deeply misunderstands both manufacturing and software.