The Joshua fight is what really gives Dubois that confidence, in that round he was also hit by Joshua and I thought that Dubois might go down. But he keep his composure and that is the mistake of Joshua as become the aggressor but was caught by the huge power by Dubois.
That was the first time I saw a fighter who was not afraid of Joshua's power and reputation. Dubois just go there and attacks Joshua as if he doesn't care if he gets knocked out with Joshua's power. Joshua was so confident before the start of the fight; his overconfidence ruin his strategy
However, if Dubois has gain a lot of confidence in his last 3 wins, Usyk though has a back to back fight with Fury and won both of that. So I guess it's the experience vs the more hungrier boxer match. So we will see which one will prevail, but in this scenario, usually the more experience and seasoned boxer won and remain the top dog until he lost his prime.
I prefer to ignore the first fight and just focus on their performances after their match, and for me, Dubois is the one who improved a lot but he needs more than just power; he needs endurance because Usyk is always ready to last the whole 12 rounds.