Just watch this little video. Goku is not on this clip until near the end but it will give you an idea of what Goku is capable of. Currently, Goku is way more powerful than that big guy with yellow hair. Current Goku will tap this guy on the forehead and kill him. Here is another video of what Saiyans are capable of. https://youtu.be/NLtbZr-euhQ?t=606 They can blow up planets effortlessly. Again, in his most recent form, Goku will treat this bad guy like an ant.