I can honestly say that Neopets taught me a lot of valuable skills, especially in business. I learned how to run my own shop, invest in the stock market, and even make websites. The customization options on Neopets, especially the Neopages, helped me learn HTML/CSS, among other things.
Virtual pets can also teach you how to take care of animals and many other important skills. It's a great foundation for learning how to care for a real pet. Some pet sites even have knowledge bases where you can learn more about the site itself.
The community aspect of most pet sites is another key learning experience, as it teaches you what a true community is. Connecting with and meeting other users helps you understand how to relate to people better and form meaningful friendships. I believe this is a huge skill to develop, as it’s valuable both online and offline.