Toriyama, as an artist, is an illustrator and a comedian. It is by channeling these two talents, filtered through his personality, attitude, and sense of humor, that he tells the stories he does, the way he does. It's all common adage by this point: he's a whimsically spiteful bastard who likes to amuse himself, writes by the seat of his pants, subverts expectations, names characters in accordance with elaborately thematic puns, writes characters who feel sincere and organic, blends genres incredibly well, etc. It is this personality and style directly from which Dragon Ball sprouted. His personality and style are what make Dragon Ball what it is. Without Toriyama, what is calling itself Dragon Ball is lacking its essence, its soul. This doesn't preclude said work from being good, it simply means that it would feel distinctly "un-Dragon Ball", under the hood. This also doesn't preclude a damn good imitator, but imitations are still imitations.
Animated works, be them adaptations or original, can be used to enhance his manga's artistic value, and I don't think that they come with any inherent blemishes. Voice actors can contribute by using the manga as their script, and animators can contribute by using his panels as storyboards. Toriyama can even provide additional creative input by doing new character designs and making casting decisions.
Live action is a different beast entirely. Toriyama's not a director, and he's not a cinematographer. Unlike animation, his manga can't form as much of the foundation of a live action film. At the very least, though, this revival has shown that, in addition to things he already contributes to for animated works, he can write the screenplay. However, if you wanted a truly proper live action Dragon Ball, you'd also need someone who could direct in a way that delivers jokes the same way he does, a cinematographer who could shoot action sequences in a way that flows like his manga panels, and so on. The product, even if in a different medium, needs to retain that core, that signature artistic creative essence, as much as possible, in order to be a truly authentic extension into a new medium, in order to really feel right. Beyond that, you can't really capture his art. That's something that couldn't really be imitated by, or translated to, live action, I don't think. Likewise doesn't preclude some damn good attempts.
Hot Take:
I'm actually morbidly curious to see how Toriyama's directing and cinematography would look. I know they're well outside of his trade and comfort zone, and it would probably not be very good (and no, I'm not suggesting that making Toriyama do everything himself would be the right thing to do), but I just want to see what it would be like. He's still a comedian, after all. It couldn't be that bad, right?
