I think there is to many what ifs in this? And if there lives are changed just to many to factors IMO. But Steve can do pretty well as long as his character is still the same.
I mean Steve when the chips were down. He would use prep from others like Army weapons, Shield tech, Avengers tech, Jets, Ironman armor, Tony Starks vibranium shield, energy shield, to even SHIELD itself. Or even on the "fly" prep by picking up Thor's hammer. Through out his career he definitely would get resources and easily to boot. Even a entire intergalactic army against future Korvac because of his ability to be a leader and coordinate efforts to bring him down.
His character and leadership gives him many teammates and many....many resources or options for some of the worst case scenarios.
The old saying, " I know a guy that knows a guy."
Spiderman doesn't really have the type of resources or connections that Steve can achieve easily. So I can see him failing a lot of Steve's battles/missions if he tries to go "solo." He's more of a loner in comparison. Yes Spiderman has worked on teams, to even lead teams and has friends that can provide resources but nothing re motley the same in comparison to Steve.
Pete might gain the SSS abilities. But he can't acquire the character traits and personality that allows Steve to gain the trust, admiration and respect of many. That you either have it or you don't.
Steve was born with it.