I'd actually argue that's not how Kovalev fought Hopkins. Kovalev fought relatively cautious against Hopkins, always coming in behind his jab and trying to avoid Hopkins' traps. It's by far the most cautious fight we've seen Kovalev fight (and it was smart and allowed him to win essentially every round). When he did get over aggressive and Hopkins landed his sporadic counters, Kovalev would reset, take stock of things, and then get back to coming in methodically behind his jab. It was a very measured performance as opposed to a balls to the wall reckless one.
I never said that you ought to fight like a fool to beat the likes of Mayweather or Hopkins.
I only brought up Maidana as a recent example of a man that gave no respect to Mayweather. Castillo was another one, and he possessed far more skill than Maidana, and made it a fight against Floyd. Ultimately Maidana was just way too easy to hit and his offense was way too crude to land more consistently on a boxer like Maywaether. If he was a more skilled boxer with a more measured approach, with the same attitude towards taking the match, we could've been talking about a very controversial decision. If some bumbling fools gave Maidana and Alvarez a draw, imagine what could've happened in a fight that was actually close. The Mayweather style just doesn't impress judges that favour aggression and hard punching.
Coming in behind the jab and making yourself a difficult target for the counters is obviously a major part, along with the fact that a Kovalev can actually hurt Hopkins while Hopkins cannot hurt Kovalev, the same way that a Golovkin can hurt Mayweather without getting hurt by Mayweather. It means that as long as you have the will to win, you can stay in the fight, if by no other means than throwing 100+ punches a round, regardless of where they land. These Eastern Euros are not going to be so easily discouraged from winning and they certainly give no respect other than what is earned in the ring. An American superstar to them is nothing more than a man that has been put in front of them to beat.
Plus Hopkins is 50 years old FFS.
He might be, but I reckon he would've still beaten the majority of light heavyweights, the same way that Mayweather would beat the majority of middleweights. Just not Golovkin, in my opinion. Not at this age, not with this style. You need to look past the legend of Mayweather being "unbeatable" the same way that Rocky Marciano was "unbeatable", and look at the match-up itself. 39 year old man, with no punch, with slower legs and reflexes than he used to have, it's not even a question in my mind, unless you believe in the myth of Floyd being the greatest boxer ever.