Not sure I agree. I've seen people do that and they inevitably end up spending thousands on repair and maintenance the last few years of the cars life. Had they sold 'in time' and bought something used, but slightly newer and more reliable, I'm pretty sure they would have ended up ahead.
If you have the time/skill/equipment to do all your own repairs and maintenance it might be OK, but otherwise keeping an old car on the road gets expensive.
I recently replaced the water pump in the 2014 and the dealer quoted between $4,500-10,000+ for replacing the pump or replacing the engine if the coolant being where it's not supposed to be broke bearings or anything else. I got a second opinion from a small independent shop and he took it step by step and confirmed no engine damage before I committed to the pump replacement. It was around $3,500 total.
Replacing the vehicle would have cost $20k plus, so the math made sense for me to repair. If I was looking at an engine replacement might have gone the other way.
Keeping up with routine maintenance is the most important thing and even then random things do break.
One of ours is a 2006 with just over 230k miles on it (Toyota). The last few trips to the shop for just an oil change and tire rotation has turned into large bills to fix things. I don't think if we sold it earlier we'd come out much ahead but maybe I'm wrong.
We plan to replace this with a similar 2-3 year old model and drive that one into the ground. Our other is a Ford and has not been as reliable. That will be replaced with a Toyota when it's time comes (which sadly may be with a lot less years/mileage than the Toyota).