Someone in their 70's can drop $100k because a warranty is more than a want, yet can't afford to pay for repairs. Sounds like a, "want."
It's not about paying for the repairs, JFC. It's about the security of holistic coverage, which typically includes a loaner vehicle, roadside assistance...etc. My dad paid for the repairs on his Expedition for 20 years. More recently, those repairs got more expensive and more frequent and the vehicle's reliability became questionable. And there was the real risk of it breaking down between the house and the cottage, or coming back from a doctor's appointment in the middle of winter.
This became challenging without the availability of a loaner vehicle in the winter months, since their 2nd vehicle (a 2003 Town Car) has never been winter driven and isn't equipped with snow tires. So they were relying on others (like me) to ferry them around when the Expedition was in the shop.
So, part of the peace of mind of buying new was not only warranty and reduced likelihood of experiencing issues in the first place, but also the availability of a loaner vehicle as part of that package, on the off chance that it did end up in the shop. You may not prioritize these things in your life, and that's fine, but my family sees them as important in ensuring the safety and security our our elderly parents, while also working to meet their needs in terms of capability and comfort.
Again, if you are going to ignore depreciation, opportunity cost, because you have made up your mind to either pay $100k + interest or $100k in cash. This isn't a financial planning discussion anymore. Want vs need. Buying cool toys is fun, just understand it isn't a need.
Bro, the discussion was *IF YOU ARE SPENDING THE MONEY ANYWAY* and, *IN THAT SCENARIO* whether it was better to finance at low/zero interest, or pay cash. I've argued that it's better to finance if the cash you are going to be spending is already working for you.
It's not about the amount being spent, it could be $50K, $40K, it doesn't matter. If the same amount of money is being spent, which is the better decision?
@rijndael argued that the financing made more sense and I agreed with him and have articulated why I believe that to be the case. Instead of addressing that scenario as presented, you've taken us off into the wonderful world of whataboutism where other options, not presented, like not buying a vehicle, or buying a used jalopy that already suffered from massive amounts of depreciation, are on the table.