Regardless, it becomes clear that the MCU version of the Captain America super serum does not stop the aging process of Steve Rogers in the same way as it did in the Marvel comics.
The super soldier serum is supposed to heal a person from all things that can harm the body and prevent anything that would effect a normal person on the cellular level, and slows aging in the comics context.
Steve Rogers was the first and only recipient of Erskine's perfected serum, granting him superhuman abilities, curing all his medical ailments, and significantly increasing his height and physicality. It also increased his lifespan, allowing him to survive to be over one hundred years old.
The Super-Soldier Serum dramatically prevents individuals from aging due to the regeneration of healthy cells. For instance, Dr. Kudrin has stated that Natasha "don't age as fast."
The MCU's Natasha Romanoff was never given the Super Soldier serum like her comics counterpart. Black Widow shows why Dreykov made this choice. Despite receiving the Super Soldier serum in the comics, the MCU version of Black Widow was never enhanced beyond peak human capabilities.
Throughout the comics, Black Widow has demonstrated several superhuman abilities, including an anti-aging medical implant that allows her to appear and act young and vital for decades.
Bucky Survived Through Cryogenic Freezing And The Super-Soldier Serum. After surviving his fall from the train, Bucky would be kidnapped by a HYDRA cell in the Soviet Union, and then placed in the same super-soldier experimentation that Steve was.
Bucky was born on March 10, 1917, so he was already older than Steve, who was born on July 4, 1918, even before they became enhanced. Further, Captain America was frozen and preserved as he was in 1945 without thawing for nearly seven decades before he was revived.
Bucky Barnes, like Steve Rogers, has lived for several decades due to cryogenic freezing and the super-soldier serum. Bucky's life expectancy could potentially surpass Steve's 116 years, depending on circumstances. Despite outwardly aging at the same rate as Steve, Bucky can still live for at least another 80 years.
Serum enhances the strength and ability of human. Now bucky was not weaker than John, but we can see the fact that even at his human level John walker had better training than Bucky. He was so good as fighting before even getting the serum. So he was able to fight better than bucky.
In terms of raw strength, Captain America is typically portrayed as being stronger than the Winter Soldier, although the Winter Soldier's combat skills and agility can still make him a formidable opponent.
In the Marvel Comics, Steve Rogers appears able to live forever without aging. While he can be killed, he has lived for huge periods of time without aging at all because of the effects of the super serum and how it interacts with his cells.
Thor. Thor, the god of Thunder, was undoubtedly the most powerful member of the original Avengers. His power continues to grow in the Marvel Cinematic Universe.
Steve Rogers (Captain America) does age. The super soldier serum slows the negative effects of aging, but he ages. Marvel utilizes a sliding or floating timeline designed such that the first appearances of the characters in the 1960s comics all happened between 10-15 years ago, in the comics.
Unlike some characters, Bucky does have a canonical birthday: March 10, 1917. He's a little more than a year older than Steve, which makes him the oldest human Avenger at a chronological 106-years-old.
They clearly succeeded in Wakanda because the next time he showed up, he was living in a hut in Wakanda, and the kids living around him nicknamed him the White Wolf. This nickname was just something the kids gave him, as Shuri (Letitia Wright) still called him by his real name.
This has granted the Winter Soldier both superhuman strength and some other powers. Bucky was injected with the infinity formula, which has granted him semi-immortality and superhumanly enhanced strength, speed, reflexes, healing, stamina and agility.
Bucky isn't ageless. In fact the reason neither of them appears to have aged is actually, more or less, the same. Steve was “doing time as a Cap-sicle” for most of the period between WWII and the Avengers, while Bucky was kept in cryo-stasis when they didn't need him for a mission.
Bucky was a hero who fought alongside Steve Rogers in World War Two. But when he was captured and brainwashed, he became an assassin known as the Winter Soldier. It took him a long time to become free and after that, he had a hard time dealing with the things he had to do while he wasn't in control of himself.
Based on what can be deduced about his species' aging, it is possible that Groot is around 14-18 years old in The Guardians of the Galaxy Holiday Special.
In Thor: The Dark World, Odin reminds Loki that Asgardians are not immortal and have lifespans as humans do, to which Loki responds: "Give or take 5,000 years." From this, it can be calculated that Asgardians live to about 5,100, with Loki being around 1050 years old in the MCU.
Born on May 29, 1970, the iron avenger was 38 years old in his first movie, making him 50 as of 2021. However, as Avengers: Endgame was set in 2023, he would have been 53 when he sacrificed his life to beat Thanos.
