Why Bucky Is So Much Weaker Than John Walker | Screen Rant
Warning! Spoilers for The Falcon and the Winter Soldier, episode 5, "Truth", ahead, including Bucky and John Walker's storylines.
The Falcon and the Winter Soldier episode 5 opened with the heroes trying to reclaim the shield from John Walker, but during the fight, Bucky was noticeably so much weaker than the rogue Captain America — why? On the heels of the public meltdown of Walker in Latvia that left one Flag-Smashers member dead, Sam and Bucky took it upon themselves to reprimand the government-appointed Star-Spangled Man for what he did. While they tried reaching out to him at first to convince him to give up the shield, the situation quickly escalated, resulting in one of the most brutal battles that the MCU has had thus far.
Containing Walker was no easy feat. After his humiliating fight against the Dora Milaje of Wakanda in episode 4, followed by the opportunity to inject himself with a dose of Super-Soldier Serum that the Flag-Smashers had yet to use, he had become much stronger. While he was trained as a military man, before he became enhanced he couldn't hold his own against physically enhanced beings and proper superheroes, which wasn't good for his ego. So in the end, Sam and Bucky had to partner up to take him down, although they did have their separate chances during the skirmish to fight the new Captain America.
Sam made some solid hits and, for someone whose physicality is not enhanced, he did a good job against Walker. What's interesting, however, was seeing Bucky struggling against their adversary considering that he, too, was enhanced by a different kind of Super-Soldier Serum. Seeing him taking down goons in Madripoor earlier in Falcon and the Winter Soldier proves that he has the ability to go on a slugfest but, for some reason, he wasn't able to quickly take down Captain America. It's likely because he was still exercising some self-control throughout the whole ordeal. Over the years as the Winter Soldier, Bucky operated ruthlessly, killing anyone who stood in his way. As someone who's still struggling to move past that, he's careful not to slip back into his old ways, potentially undoing all the progress he's had ever since he started his rehabilitation. As he said later on in the same Falcon and the Winter Soldier episode, he feels like the Winter Soldier is still inside of him, and he's afraid that one lapse in judgment would release the killer.
Walker, on the other hand, didn't have a care in the world while fighting both Bucky and Sam, and even came close to severely hurting or killing them in the same way he did the Flag-Smasher. He was still reeling from the death of Lemar Hoskins/Battlestar and, while he'd calmed down a bit after his earlier murder, the heroes' attempt to reclaim the shield put him back on the offensive. While fighting, the disgraced Captain America's only goal was to keep the mantle; Sam and Bucky's attempt to reach out to him as a way to get ahead of him. Without Battlestar, he didn't trust anyone as he presumed that they would only betray him. So while he's officially stripped of his title as Captain America, not to mention the benefits as a military man, Walker will only become more dangerous, especially with someone like Contessa Valentina Allegra de Fontaine pushing him further down the dark path.
At the end of The Falcon and the Winter Soldier's penultimate episode, Sam and Bucky go their separate ways. While the former focused on preparing to properly assume the Captain America mantle, the latter will continue working on his rehabilitation. A big part of that is making amends for people he wronged. Only then will he actually be able to finally move on from his days as the Winter Soldier.