Is the Toyota Vitz’s popularity to its detriment, or is it a wise long term investment?

For years, the Toyota Vitz has been a popular buy for people looking for a reliable, economy car. But, since it has become so popular, there are many used Vitzes out there any given time. Yet some say this abundance is bad for resale values, because supply outstrips demand. However, some argue that the Vitz's reputation as a model that has low running costs and lives longer than many competitors makes it a good long term investment that retains its value better than many competitors. Do Vitz owners get good return on their investment, or should they consider more rare options? What is the Vitz’s resale value compared to other cars in its class and what factors should potential buyers be considering when looking to future resale?