Dragon Ball has long featured the Super Saiyan power boost as a major enhancement for some of the chief heroes in the franchise. But despite all that prominence, it still has a couple of confusing elements that make it a bit weirder then it should be.
Here are all the ways the Super Saiyan forms don't make sense within the Dragon Ball franchise.
DEVELOPING POWER
Going Super Saiyan is initially established as a major emotional milestone for Saiyans. It requires them to go through a massive emotional turmoil before they can unlock and fully utilize their abilities. Goku had to seemingly lose Krillin forever, while Vegeta was forced into a pure fury by his own self-hatred at not being able to keep up with Goku's power level. Future Trunks saw his mentor and father figure Gohan die, and that loss fueled him. While teaching Gohan how to achieve the form, Goku even described the transformation happening as "needing" power more than just desiring it. Gohan achieves the form for the first time while fighting his father, and becomes furious at himself for never protecting himself.
But then the Buu Saga happened and threw that idea out of whack. Kid Trunks and Goten are introduced as young prodigies, to the point where they can already go Super Saiyan by before they're even ten years old. The passionate moment that fueled their transformations? They were training with their parents and they got hit. It's a very minor trauma to motivate their transformations, which is especially confusing because of all the trauma that Goku suffered in his own childhood.
The original Dragon Ball saw Goku of the same age as Trunks and Goten fighting entire armies, losing his closest friends and taking down evil kings. He went through far more trauma than both of them combined, yet apparently was never angry enough to reach Super Saiyan. Even if the argument is that Goku and Vegeta's enhanced power levels at the time of their conception could have influenced their power levels, that flies in the face of how Saiyan genetics seems to work in the rest of the series. It's just weird that Goten and Kid Trunks gained a power boost in peacetime that Gohan took years to achieve.
NO WEAKNESSES
One of the most unique aspects of the Dragon Ball franchise is how different styles of combat can come into play. Certain characters possess specific abilities, ones they can use to counter or defeat their opponents. What helps is that most of them have some form of workaround. Stuff like the Destructo Disc and the Special Beam Cannon can easily miss their targets, the Tri-Beam and the Kaio-Ken deplete physical strength the more they are used. Even the catch-all Kamehameha Wave can be deflected or overwhelmed by a more devastating attack.
But there's really no weakness to the Super Saiyan form, giving a certain group of characters an absurd advantage as the series continues. At most, the form requires a great deal of stamina and a sufficient enough blow can knock someone out of the form. Beyond that, there's not too much holding the user back. But after training in the Hyperbolic Time Chamber, Goku and Gohan have the ability to just casually have the power boost as a permanent advantage. The form only escalates from there. The only Super Saiyan form with any real additional drawback is the Super Saiyan 1.5 form that Future Trunks uses in his fight with Cell, which elevates strength but at the cost of speed. The power-up quietly made it difficult for Dragon Ball to really set up tension in most battles as a result.
The Super Saiyan form has always been established as the ultimate form of power within the Dragon Ball franchise. Each time a new form of the power-set is achieved, it's suddenly the biggest development for the characters. And inevitably, there's always another level to be reached, another Super Saiyan form to be reached. It's kept much of the franchise from finding new and exciting ways to enhance the heroes, such as unique powers or transformations. Ultra Instinct is a compelling power boost for Goku thanks to the specific speed boost it gives him, but it'd be more interesting if there was more similar variety. From a storytelling point of view, it makes no sense to keep finding new levels of Super Saiyan.