"He got know that, blood or talent alone never gets the job done."- I can agree with that.
But Until DBZ they were the strongest of the universe. When you are a top henchman for the emperor of the universe, you will surely be arrogant. Well Goku saved the universe multiple time but he is a fight monger under all that goofiness. And there is Vegeta, who has a burden to restore his whole planet and save their race from extinction.
They just "thought" they were the strongest. Truth is, there's always someone better in some corner of the world. And top henchman or not, you should always try to get better at what you do, better than who you were yesterday, in one way or the other. Even 0.01% of progress is better than nothing.
So, once more, Goku stayed consistent, from childhood to present time, that's why he's still at the top. He never said yeah this is enough, I should or "I can" stop for now.
Whereas Vegeta realized it all a bit late, he has been "kicking it" for a bit too long, that's why he's been playing catch up for so many years. But tbh, if he keeps up the pace, he just might surpass Goku.
Yet, it's all up to the writers. They're actually the most powerful ones in a certain Universe, then comes the characters they choose and how they choose to write them.
Yeah, the writers and Akira Toriyama, will never let Vegeta pass Goku I think. But Vegeta's new from Ultra Ego sound promising. And then Majin Vegeta was badass but I dont count it as his accomplishment.
They all do have big plans for Vegeta, a lot of people are talking about it. We'll just have to wait and see how it goes.
Hoping for the best