Originally Posted by
ZeroBG82
I would argue that MCU Bucky is in entirely the wrong headspace to be Cap, and he knows it. As FaWS shows.
But there is a bigger issue in play.
Bucky couldn't be Cap in the MCU for the same reason he had to give it up in the 616, being publicly outed as the Winter Soldier. No matter what you do with the rest of your life, being a HYDRA/Soviet assassin for 70 years makes it impossible in the public eye.
A subset of the population is never, ever going to accept the brainwashing story. Period. He'd never not be an enemy of the state to a good chunk of people, and there would always be a question about his loyalty among those who don't know him well. Even the MCU's version being pardoned doesn't change the perception there.
He can be Cap's partner, but the shield is off the table.