We've put a little under 150,000 on my 1960 GMC in the last 19+ years. It was my semi-daily commuter for 9 years, 72 miles a day. Before that our 1946 Ford sedan street rod covered 300,000 miles in 8 years. I had a friend with a new Toyota wagon. After seeing all the miles I put on the 46, he got rid of the Toyota payments and bought a 54 Chevy pickup for his daily driver. He lived close to work, so he just restored it to stock with a few rust repairs and fresh paint.
IMHO there's nothing crazy about it at all. Just build it to be practical. Another benefit of an old truck is if anything gets banged up, you can just take off the part and replace it. Not very easy or practical with a new vehicle.
