I believe that Pokemon's appeal lies in how easy it is to enter and how much there is to do.

You can play the games, watch the shows, collect the cards, or whatever combination works for you. Each one of the four has its own appeal, but all of them are connected through simply catching and training Pokemon. Some people tend to focus in on the battles and strategy of battling and others simply find new creatures for their collection.

There are so many different types of Pokemon, so everyone must have some favorites ultimately.

It is also a format that has staying power. There are continually new games, and new Pokemon are still being generated by the creators of the games. People who used Pokemon when they were kids can still often find ways to engage with Pokemon as adults. Nothing that Pokemon produces is just for one age group or one kind of player. Some players want the best pet. Some players want to see everything, and to collection and connect to everything about what they collect.

Others simply enjoy the stories, the world building. The art, the sounds; everything is consistently the same and it makes it easy for those connected to it to continue anywhere.

Regardless of how someone encountered Pokemon, there are many ways to engage with Pokemon without having to start over every time.