MCU Characters, and their fate in What if...?

What if...Captain Carter was the First Avenger?

Ultron:

Since Peggy returned, she would have knowledge to Ultron and ask Tony not to make it. But also, Bruce isn't in the Avengers, meaning he wouldn't help in making Ultron anyway. 

Vision:

With no Ultron, there is no Vision. 

Nate Barton:

The only change is that his middle name isn't Pietro, since he didn't die. 

FRIDAY:

Tony had no use for her since JARVIS is still active. 

Scott Lang:

Scott wasn't needed by Hank. Read Hope's for why. 

Hope Van Dyne:

The Wasp is confirmed to be in the Avengers, instead of Hulk. Who knows how. It's unlikely it's Janet, which means it's Hope. Seeing as she's been an Avenger for 3 years at this point, Hank could have a little more faith in her to complete the mission for him. 

Hank Pym:

Noted above. 

Janet Van Dyne:

Since Scott isn't around and never went subatomic, Janet couldn't make contact with him, leaving her down there. 

Cassie Lang:

Since Scott never became a hero, it's possible Scott can be a dad to Cassie again. 

Darren Cross:

Darren could have been defeated by Hope, easily. 

Maggie Lang:

If she goes on her word, she will let Scott see Cassie again, once he gets a job. 

Peter Parker:

In this universe, there is no Bucky to save, or Sam, or Scott. So team Captain Carter would just be her, Hawkeye, and Wanda. I don't think there would be a war since it started because of Bucky. Anyway, this means Tony has no need to recruit Peter. 

T'Challa:

T'Challa doesn't attack Bucky, since there is no Bucky. 

T'Chaka:

It's unlikely he would die. Zemo killed him to frame Bucky, but there is no Bucky. 

Baron Zemo:

Since Sokovia wasn't destroyed, he doesn't get revenge on the Avengers. 

May Parker:

Peter is never an Avenger, no Avengers, no Strange, no Strange, no May dying. 

Maria Stark:

She could've possibly lived since there's no Bucky. 

Adrian Toomes:

Spider-Man did not have the power to stop Toomes. 

Killmonger:

With T'Chaka alive, Killmonger likely would've killed him. 

Ava Starr:

Ava would not be healed since Janet never returns...goodbye, Ghost. 

Bill Foster:

Depressed because Ava died. 

Jimmy Woo:

Well, there's no Scott to arrest, so he has no connection to the story anymore. 

Quentin Beck:

Peter has no connection to Tony anymore, so Quentin just suffers. 

Agatha Harkness:

Since there is no Vision, and Pietro is still alive. Wanda doesn't get depressed and doesn't take over the town, which means Agatha never finds her. 

Billy Maximoff:

Doesn't exist. 

Tommy Maximoff:

Doesn't exist. 

Sharon Davis:

No Agatha, no Witches Road, she lives. 

White Vision:

No Vision, he doesn't exist. 

Joaquin Torres:

There is no Sam, so he doesn't have connections to the Avengers, or become Falcon. There was no Falcon to begin with. 

John Walker:

It's unlikely he becomes US Agent. If we assume Peggy time traveled to be with Steve, it's unlikely they would get an American man to become the new Captain Carter. But there is no time travel, since Scott decided that. 

Isaiah Bradley:

With the super soldier serum being used on a woman, it's possible it was used on more woman, as opposed to men. Unless they did both. If so, Isaiah can go unchanged. 

Valentina Allegra De Fontainne:

Val doesn't have Ghost, or John, so she has no purpose. 

Yelena Belova:

Natasha isn't on the run, but she likely called Natasha for help anyway. Since the blip happened, but Scott isn't there for time travel, Yelena is now dead. 

Alexei Shostokov:

Doesn't join the Thunderbolts or anything really. 

Melina Vostokoff:

Melinda died in episode 5 of season 2. 

Taskmaster:

Black Widow can happen without Melinda, so I guess Taskmaster is still saed. 

Dreykov:

Without Melina, Black Widow and co. must find a new plan to defeat Dreykov. 

Kamala Khan:

With the blip happening, Kamala never found out about Captain Marvel. So she gets the bangle but doesn't become "Ms. Marvel." 

Jeniffer Walters:

Bruce isn't around, so who knows what happened to her.