I do! Granted, I've been playing the 3DS a lot more than my DS, but when I do play, I mainly play my GBA games. Typically the games that I play is Pokemon Sapphire. To me, GBA was one of the best consoles and I found that the games back then were pretty inspiring and classic. I love the pixels that GBA games have on DS's rather than the newer graphics. (I'm weird like that!)
Yes, both the GBA and DS are legendary handhelds with a great library of games. I've got plenty of GBA games that I still play to this very day. I don't think I'll ever stop playing them, the DS provides that extra level of convenience. It's a pity that Nintendo didn't provide backward compatibility for GBA games on the DS. Very short-sighted in my opinion as there's a huge market out there for GBA games.
I don't have that may GBA games anymore, but yes I still play Pokemon Blue like crazy in my DS. For some reason I love that game more than I love all other Pokemon games.
I just never got with the whole Pokemon Go thing. Probably because I have never played, but yes I do still play my games in it. I broke my GBC a long time ago, but if I had one, I still wouldn't use it.
This is one of the things I love about the DS, I can still play the games I have for other systems. I actually have quite a bit of GBA games laying around and I have a couple go to ones that I still play sometimes. It is usually down to car rides as the only time that I really play the DS anymore, but I do know that I am going on a trip here next month so this just might be thing to tie me over. Thanks for sharing.
Unfortunately I have a 2DS so I can't play my old GBA games, unless they're downloaded from the store. But I still play my old GB games on the GBA. All the time my mum almost freaked out because I kept asking her to buy me batteries for the GBC... god bless GBA and its rechargeable one