The Saiyans have long been at the center of the Dragon Ball franchise, even it wasn’t always apparent. The revelation that Goku was among the few survivors of the race was a major shift in terms of scope for the series. The Dragon Ball universe has expanded, but the Saiyans have remained a largely extinct species, with the only survivors calling Earth their home.
With the wish-granting Dragon Balls, the series’ Saiyan heroes could probably restore their homeworld and their people. However, given what we’ve seen of the Saiyans of Universe 7, it’s probably for the better that they’re all dead.
The Saiyans are a race of powerful and natural-born warriors. Originating on the planet Sadala, they eventually turned to conquest and defeated the Tuffles – taking their world and renaming it Planet Vegeta. The species became increasingly dangerous, becoming mercenaries who traveled the galaxy and conquered other worlds – eventually becoming part of Frieza’s empire. However, Frieza eventually grew concerned with the potential of the Saiyans, especially the prospect that they could eventually change sides and use their power to usurp him. Frieza eventually traveled to Planet Vegeta and, despite the best efforts of people like Bardock, wiped out Planet Vegeta and all of its inhabitants.
Only a handful of Saiyans were off-world at the time of the attack, notably Kakarot – a young Saiyan who landed on Earth, gpt amnesia and grew up to become the heroic Goku. Dragon Ball Super reveals this didn’t need to be the fate of the Saiyans. In the alternate timeline of Universe 6, the Saiyans never actually left Sadala. The Saiyans from Universe 6 kept evolving in a unique way, eventually losing their tails and access to the Great Ape Form while also fully discovering the Super Saiyan transformation.
They became less dangerous and more heroic than the Universe 7 Saiyans, with whom they formed something of a friendly rivalry with. But does the proof of a heroic Planet Vegeta prove that that the heroes of Universe 7 should restore their version of the Saiyan race?
It’s important to remember that for the most part, Saiyans were a brutal and dangerous race. The species valued battle above all else, to prove their own superiority and gain monetary reward. If the Saiyans were restored, they’d likely resume their attempts to conquer the galaxy – or at the very least, become enemies of Frieza and plunge the galaxy into war. Another worrying detail is the fact that the more villainous Saiyans could learn about the Super Saiyan transformation and try to develop their own version of that power upgrade. Having an entire army of conquerors with Super Saiyan powers would be incredibly threatening to the continued peace of the universe, and could even endanger the powerful (but potentially outnumbered) Saiyan race.
One of the biggest themes of the entire franchise has been the ability for people to develop and grow as people on top of improving their fighting skills. Change is a crucial part of that, with many former villains and antagonists becoming dedicated allies and friends as the series goes on. It was being on Earth that taught characters like Vegeta the importance of letting go of their furious side and tempered his darker Saiyan impulses. The Earth-bound Saiyans had the chance to survive, thrive, and grow – becoming some of the most powerful figures in their entire reality.
But are most of the Saiyans capable of such change? It seems they’re unlikely to simply find that kind of peace, at least willingly. They could even find a new version of Giant Ape Form and devastate worlds all around the galaxy. If anything, their influence could end up having a negative effect on characters like Vegeta, who could backslide into bad tendencies if the people he used to help rule over were to suddenly be restored. There’s too much of a threat to the Saiyans returning, and it’s better that the majority of the race stays dead.
The Saiyan race in Dragon Ball may have produced some major heroes, but that doesn't mean the dangerous species should be restored.