Kovalev beating Hopkins isn't any more impressive than Foster beating Tiger. Given that Tiger continued to have some success at the world level, I actually think Foster's win is better. I doubt Kovalev lasts the distance against Foster.
I remember when I first saw him. He was seven-foot-three, 118 pounds, and the only bantamweight in the world who was KO'ing light heavyweights completely switch-off cold. You knew who you were then. And you knew who he was. Because everyone knew his name if they knew him. He didn't keep it a secret.
The fact that Hopkins held on for so long at 175 is more indicative of what a wasteland the division was. The likes of Pascal, Shumenov, Cloud and even Dawson are amongst some of the worst strapholders in the divisions history imo, though not all will share that view. What Kovalev did to Hopkins is exactly what a fighter of that reputation and ability level should be doing to a 50 year old, even that version of Hopkins. Hopkins looked done. He was hugely diminished in years prior even, but still had retained his IQ and more importantly some his smart offensive timing and defensive reflexes/discipline etc, though nothing like what he showed to have left vs Tarver, Pavlik, Calzaghe and the like. And he was no longer a great fighter even then in a historical sense imo, more like a very good one. That a supposed champion like Cloud could look so clueless is damning. Or Pascal throwing ten punches a round vs a man twenty years older than him. The version of Tiger that Foster beat was better than the version of Hopkins that Kovalev beat without question, as shown when he went on to outbox the still serviceable version of Benvenuti. He was still a skilled, formidable fighter and was looking ok until Foster poleaxed him.Hopkins on the other hand....his mind and grit were still in tact against Kovalev along with a bit of his old technique, and he was in the best shape he could be in at that age. But he looked really poor otherwise, which is impossible to hold against him. Rondon, Fourie, Finnegan, Quarry etc were all better at 175 than the late version of Hops imo. Fourie especially and Finnegan were very skilled technicians. Fourie got the post-Ali version of Foster who was very much on the way down but he still struggled to win many rounds out of 30 over two fights. Part of that was the size difference, mind.