Why do Game Boy Advance Pokemon games get corrupted and get deleted more than DS Pokemon games do?

I'm really confused. I really love Emerald and when I defeat the Elite Four, after the credits, it gets corrupted and deleted. Can someone please explain why. And I heard that the Pokemon Company is making new games. What are these games and if they are remakes of the Hoenn games. Thanks!|||Probably because the DS games are more advanced technology wise than the previous games