On skillset, arguably top 5 - throws every punch in the book with superb technique, unbeaten, loads of title fights, has great fighters on his résumé (yes, I'm aware of the timing and context of when he fought them) and has the greatest consistency of defensive responsibility throughout his career on film, IMO. In terms of résumé and activity, I probably agree with @McGrain - you could place him anywhere from Top 15 - 30 and I wouldn't care too much to argue, even if I may disagree. When people say he's the greatest to ever do it or as great as the Robbis, Peps, Grebs and Armstrongs, even Duran and Ali, I disagree.
From my understanding people rate Ali and Duran higher. Possibly SRL as well. On occasion Uysk but I imagine Floyd would be the majority there.
Top 30. The top 20-15 or so is just too filled with resume monsters for him to be there imo. Guys with 2 or even 3 times the amount of depth like Moore, Armstrong, Pep and Canzoneri, guys whose 4-5 best wins are all better than any of Floyd's like Charles, Ross, McFarland and both Leonards, as well as guys in between. In some monstrous cases like Greb and Robinson, it's both. Those are mostly old timers though, who competed in far more active, harsher and competitive eras. So it makes sense. Floyd's accomplishments and resume stack up super well if you compare him to most guys after the 60's. I see no argument why Hagler or Hearns should be over him, for example. Neither have his depth or longevity, and their wins aren't so much better than Floyd's best that they compensate for that. Neither do I see cases for guys like Chavez, Arguello, Canto, Napoles, Whitaker or Hopkins over him, if we just go off resume. I can see Ali, Duran, SRL and Jones above him as far as post 60s guys go. I'd probably rate them higher in fact, aside from perhaps Jones. But I can still entertain cases that he could be higher than them, even if they're somewhat minor. Floyd excels in the area of having good records, and some of them aren't just all flash and no substance. 50-0, 5 division title holder, top 10 ranked for almost 20 years, 24 wins over 22 champions, 9-0 vs Hall of Famers, 27-0 vs top 10 ranked fighters, stuff like that. They don't tell the whole story, but they do tell some of it. He doesn't beat every post 60's guy in terms of numbers, but he does beat the vast majority of them. Where he does lack, is in beating ATG fighters in their prime with all things being fair. He just doesn't have that. Guys like Corrales and Castillo were prime and elite for their division, but far from ATGs. The genuine ATGs he fought were Pac, Canelo, Oscar and Marquez. Pac and Oscar were noticeably past it, Canelo was still green for a world level fighter (only had 2 fights vs top 10 opponents), and Marquez was blown up 2 divisions right after he had just moved up to Lightweight anyway. That does hold him back quite a bit from clearly being better than everyone after the 60s. Also hot take perhaps, in terms of overall ability he's top 10. But I don't rank in ability.
He went into the Ring top 10 in 1998 and stayed there till he retired. Beat one world champ after the other. Boxed like George Micheal sang. Top 20
Captures everything really. I rank in tiers so outside of my top 6 would struggle to be consistent on fighters from 10 - 30. I think Floyd likely sits between 25 - 30. Here's my hot take on your hot take - you could argue skillswise that he is top 5, but there's two Floyds - PBF and Money Mayweather and whilst Money sold his credentials, I suspect that had he remained PBF and faced his opponents when they were better versions, he would've racked up more fights, stayed unbeaten anyway and have a case to break 15 - 20. If he had bested Pac 5 - 7 years earlier, would that be enough to put him over the likes of Ray Leonard ? He wouldn't have the four elite wins that Ray has, but he would certainly have the longevity and the ATG in his prime on the résumé.