The Kamehameha amplifies power exponentially in its base form.
Yes, Cell revealed enough Ki to destroy the solar system after charging the Solar Kamehameha for three different internal and external monologues from the Z-Fighters; and again, even ignoring the numerous supplemental descriptions of the battle detailing that Cell had been accumulating Ki over time and that its Solar Kamehameha was of even higher caliber than the Earth-Destroying Kamehameha, Goku's fight with Major Metrallitron, the giant octopus, old Demon King Piccolo, Raditz, Frieza, Cell, Majin Buu, Kid Buu, and Fusion Zamasu all prove that even relatively uncharged Kamehamehas upscale significantly above base stats.
That is fun.
Multiple people can be wrong. Case in point...
In all honesty, I, and a select few, may be the first ones to actually read the manga rather than skim through a couple of panels on a whim, but that is neither here nor there.