Floyd was past prime when he fought Pacquiao. He was as past prime as Whitaker was when Whitaker fought De La Hoya. Pacquiao however, was semi-shot. Semi-shot doesn't mean journeyman, by the way.
Hopkins was a smart enough fighter to not let his body totally get in the way of his success. You think a boxer can stay around until 50 and still be a top guy in the division? Think about it.
The biggest names on Floyd's resume are De la Hoya, Pacquiao, Mosley, Hatton, and Genaro Hernandez. Mosley and Pacquiao were closer to 40 than 30 when they fought Mayweather. Hatton was **** at WW being knocked out both times. De la Hoya was 34 and way past it as well as nearly beating Floyd. Hernandez was 32 and old. He had previously been beaten at lightweight by De la Hoya. That was a pretty good win though for someone as young as he was.
Make no mistake, Hopkins was in good shape but it was his mental game that won him those fights. He was out thinking those guys. He was physical in spots where he seen he could shine and kept them guys wondering, is he or isn't he. That kept them from pressuring him like they should have and from there he out boxed them. Kovalev's trainer saw through that and told Kovalev to just go in there and beat him like the old man he was and that's what Kovalev did. He snatched off his cloak of invincibility and tore his ass up. Once that happened, Hopkins stopped fighting. As a matter of fact, Dawson saw that too. He just couldn't unmask him like Kovalev.
I can play the make up dumb excuses game too. Lets reverse it though. DLH, Hatton, Mosley fought a bloated, lightweight Floyd who had no business at 147 and 154. Generao Hernandez fought a 21 year old, green Mayweather.
Floyd has a very solid resume and a stellar career, I feel he is a top 25 ATG type career but not top 10.
You forgot Canelo who was considered a boxing prodigy when Mayweather schooled his ass. When Oscar fought Mayweather he was at the end of his prime but main reason he lost was because he was out of his league. At thirty four Mayweather was still taking titles not getting his titles taken.