What are you talking about, breh?
First Steps literally looks like a 1960s FF comic come to life. Also, Matt Shakman (director of First Steps) has said that his inspiration for the movie comes from the comics.
First Avenger was dope to me. Watching Agent Carter for the first time right now actually.
The human Jarvis, Howard Stark, they even got the cab rolling thru with the star on the door in a few scenes.
Throwback shyt is fun, but the difference is, the above all happens in the main timeline.
In the actual 616 FF existed alongside Spiderman and Hulk and Avengers and XMen. They were already there when the rest of the popular characters started.
To have them start off in a totally different universe where they drop in, in the mid/late 2020s is nothing close to the actual comics.
If anything, just have their origin start in the MCU present day and go from there. Or maybe have them do the space mission a few years ago and just now be emerging as their public superhero selves.