If ds games cant work here and 3ds can and 3ds is after ds then cant i turn a ds file onto a 3ds file to play it?
3DS games run on a different “chip” than DS games do. The 3DS console has both chips, so it can run both types of games on their respective chips.
For DS games to run on the 3DS chip, it would require them to be rewritten from the ground up to run on the “3DS chip”. It’s the same as telling an ant to swim like a fish. They’re both animals, but they function differently.