I typically keep a vehicle until my needs change. I've never had a one that I needed to dump due to problems. My DW starts getting tired of a vehicle at around 100k miles. She is a low mileage driver, so it takes her 13-15 years to get to that point.
After 10 years, there is significant change in vehicles than what you are driving. It may be performance or safety, but the downside is the complexity and cost of the new vehicles. I do all my own work on the carbureted toys I own but cannot justify the cost of specialized tools required to diagnose and repair these new ones.