I do remember playing SMB3 a little as a kid - not sure if I had played more modern games before it at the time or not, but I didn't really care about that. Even as a kid, Mario games never did it for me, but if there was one that clearly stood out it was SMW. I get that people were hyped over SMB3, but the way I see it, it was just a worse version of a game that came very shortly after. Personally, to this day I just don't get what's so fun about SMB3, every time I decide to give it a chance and play it for a while to try to appreciate the masterpiece people say it is, I just don't have any fun at all, or at least not any more fun than I do playing SMB1 (which is, not much). I guess Mario games really just aren't for me, but out of the ones I've played there are some I at least enjoyed (and one I loved, but talking 2017 in this case is a bit beside the point), and I can't say that for SMB3 despite having tried several times to get into it.
I always felt Super Mario World was in some ways a step down from SMB3. While it was fun and had the same amazing level design one would expect from a Super Mario game and had a lot of secrets and the ability to replay levels, the controls didn't feel as tight (it feels a bit "twitchy-er," as if Mario accelerates way too quickly), and it had less variety than SMB3 did, with fewer power-ups (and the Feather Cape was so OP that you didn't need to bother with a Fire Flower) and a lack of distinct level themes. It's still my second-favorite 2D Mario game, and is still among my Top 10 games of all time, but I still prefer SMB3 as a total package.