LogFAQs > #979604734

The issue isn't just that Goku doesn't originate from a video game or game-adjacent franchise. It's also that Dragon Ball has way too many moving parts, legally, for it to be very feasible. There's Shueisha, there's Toei, there's Bird Studios, there's Viz Media, there's Funimation, there's Bandai Namco, and other companies involved with the global production of Dragon Ball. Legally, it would be a nightmare to hash out with all the parties involved.

That said, I'm also certain that Goku will eventually make it into Smash, even if it's decades from now. Either Nintendo could mandate it, or the series gets a new director (which it will eventually regardless, as Sakurai isn't immortal) who feels differently about which characters should be in Smash.