In terms of graphics, you can definitely enjoy your DS games in better quality thanthe you would if you bought the actual handheld console.
However, if you’re only planning to use it for personal use and have no plans to make a profit off of it or live stream your games, you should be fine. While DeSmuME and its games are free, it is important to note that all of these are made by fans across the world and are actually illegal–as they are unofficial reproductions of Nintendo DS and its games.
