Captain America Get Mjolnir. By wielding Mjolnir, Captain received the "powers of Thor" as told by the enchantment on Mjolnir, also giving him the strength to wield Stormbreaker. It's pretty simple really: Steve Rogers is worthy.
One of the darkest periods in Captain America's life is when he lost his powers when the Super Soldier Serum was sucked out of his body. Maybe he has some individual flaw I am not aware of that makes him unworthy? Captain America picking up Mjolnir is one of the most thrilling moments in Avengers: Endgame, with theaters full of fans going wild when they first saw it.
Maybe Captain America did wield Mjolnir once?
Thor's magic hammer Mjolnir only comes to those who are worthy, and until now that has been only Thor.
Despite Thor's beloved Mjolnir getting destroyed in Thor: Ragnarok and him getting an even more powerful weapon — Stormbreaker — during However I was told that Thanos does end up killing Cap. Which I thought was super cool and to finally see Captain America perfectly time the Mjolnir headshot on Thanos and SAVING Thor! You can check out the scene below.