It's not really that much more advanced. It just seems that way. Some offensive fighters make defensive fighters look better than what they are. Guys are to easily defined in those two groups because they are missing too much of the opposite skill.
Not everyone can be Roberto Duran where he can have abnormal skills in both defense and offense. It is what it is. They're given limited tools and they're using this art to win fights. It is more advanced, if you look at the total body of work.
And not everyone can be Floyd Mayweather. But Duran was not the only one. There were others in that caliber. Highly skilled in both offense and defense. Yes you use what works best for you. But if you have the idea you are never going to get hit, wrong idea.
Usually, those kinds of fighters aren't given with very much in terms of natural talent, they have to use those methods to win. How else do you want them to win? Slug with a slugger? Punch with a puncher?
Box with a boxer? Then they are in the wrong sport if they can't afford or don't want to get hit. Even a good defensive fighter knows he is going to get hit. Fact is guys put more emphasis on craft then than now. Now it's about getting to the fight in shape even if there is no real game plan or understanding of movement and body mechanics
I don't mind defensive fighters as long as they can mix defense and offense like Leonard did, if it weren't for fighters like Maidana Floyd would be boring as hell. I also like unorthodox defensive fighters who take risks like RJJ and Sergio. But pure defensive fighters like Whittaker Toney and Rigo don't care for their style, boxing is more complex than 2 opposing styles and the ones who can adeptly mix the 2 together tend to be the most successful especially as far as fans go, because they are respected and loved not just respected.
I personally think it's the other way around. Defensive fighters are always getting called brilliant and anyone who is not a defensive fighter pretty much get thrown I to the mindless brawler brute caveman category. It seems no one appreciates the intellect it takes to move forward toward your opponent while throwing heavy shots (many by some (brawlers) naturally giving their opponent many advantages. So when, where, and what punches they throw has to be very carefully decided or the advantages they give will be exploited. Defensive fighters are only taking advantage of what's being given, you don't have to be a genius to do that, you just have to work on your speed and reflexes to do it.
lol, so you hate Floyd slightly more than Cotto. Come to think of it, not exactly sure why you said that but hey, whatever, cool to know.