Boxing SRL and staying a bit too passive at times wasn't the best idea. I was actually surprised that Duran did better than i thought on the outside with Hagler and Hagler went better than i anticipated on the inside. Having said that Duran's boxing skills were criminally underrated for the longest time and Haglers size probably should have been a bridge too far for Duran on the inside.
You are not wrong. Most people hold back on acknowledging active fighters as greats. GGG is great. Hagler was great as well but he would not be a shoe in to handle GGG. GGG could compete with any middle ever.