Why waste that 20%?
Because if the tool breaks and scratches a $200K Lexus, then that might be a $20K fix, or possibly even starting from scratch with a new body! Is that worth risking for a $5 drill bit they buy in boxes of 1,000 at a time? No.
Then the interview switched to some guy in America looking miserable complaining how his bosses made him use every tool until breaking point. He listed a litany of faults this caused, like off-centre holes, distorted panels, etc...
And you wonder why Tesla panels have misaligned gaps. Or why rain water leaks into a "luxury" American vehicle!
If tomorrow Ford decided to start this process it would be a decade before the market believed that hey had changed their ways. Would they survive this gap? IDK the new ford Mach-E is not selling so I doubt it but I"m not an economist. People don't buy fords because of the reliability. They buy it because it's cheaper and the risk of downtime is less important to them than the price premium. Don't forget that in order to achieve that lost resource return you must be disciplined all the time and most people/corps cannot achieve that.
PS: “It’s too expensive to save money with your methods!” Is the most common response I get from customers to this kind of efficiency improvement advice. Invariably they then proceed to set several million dollars on fire instead of spending ten thousand to avoid that error. It’s so predictable, it is getting boring.
Toyota makes some of the cheapest and some of the most expensive cars on the market. They don't "use" their reputation to do this, their reputation is the result of excellent production.
You're missing the point with Ford, which is an example of another very successful manufacturer who uses similar techniques/philosophy as Toyota, which are not similar to what your brother's machine shop does.