Brehs are severely underestimating adult Naruto. Naruto isn't only about speed and strength. They also have a lot of hax abilities.
Naruto has something called the Truth Seeking Orbs which atomize anything that they come in contact with.
Dragon Ballz characters love deflecting little projectiles away which could prove fatal because if they attempt to deflect the TSBs they will literally melt through their arms and go straight through their chest in an instant.
As you can see in the picture above, Naruto also can make his TSBs into a little staff so close quarters combat will be deadly for Goku as one misstep means a lost limb or death.
Naruto also became way more durable as he got older. At age 19 he was able to tank an explosion that made a hole in the moon without any damage in base form. He was only unconscious because he lost all his chakra.
Also at the age of 19, he took an attack that cut the moon in half to the face and emerged unscathed.
Then he defeated the guy who cut the moon in half and wanted to destroy earth in one punch Saitama style.
Naruto isn't a bum. Naruto's speed is like teleporting and his strength is immeasurable. Goku doesn't stand a chance even with Kaoiken times 10. I think he beats Saiyan Saga Goku, but loses to Frieza Saga and above.