Well...I'm not sure "better" is being used, here, technologically speaking, but instead is referring to the quality of the games. While the N64 had some great first-part games, and handful of great 3rd party games (like Goldeneye), it has a much, much smaller library to choose from overall. The gamecube's library is even less robust, and the Wii...well...again, great first party titles...
The SNES, meanwhile, has various undisputed masterpieces in it's stable, across multiple publishers. Often, it was the perfect refinement of a 2d design philosophy, offering the superior version of concepts pioneered on the NES (take...Castlevania IV). This may sound paradoxical...but I actually think it'd be the most "playable" of the systems as well. It's the sweet spot in between the stark, no-saves, no mercy difficulty of NES games - like the first Metroid - and the inherent complexity of modern 3d gaming.
I don't believe Ocarina of Time is easier to pick up and play than a Link to the Past, for example.
As far as emulators are concerned...don't underestimate the appeal of actually playing these on a couch, or the floor, in front of your TV. That sells. For better or worse, people like "owning" things, and emulators, while fine for gameplay, don't look cute sitting next to your router. That being said, you can have both. Pick yourself up a raspberry pi and you can BOTH play thousands of emulated games, and do so on your couch, in a user-friendly manner.