Homelander was not a Nazi who planned to take over the world in The Boys and yet he never had a major role within Vought International, which itself had several reasons to trust Stormfront about him.
Who does Vought trust the most?
The main reason Homelander was not given more responsibility beyond a puppet role as leader of The Seven was that Vought International did not believe that he was capable of planning his departure as Stormfront in The Boys.
What is the true purpose of Homelander?
This belief that Homelander was a tasteless jerk buying his own advertising stemmed from the reason he existed in the first place. Homelander was literally born and raised to be the public face of Vought International on The Boys.
The Boys’ Vought, in turn, didn’t care what Homelander did in his spare time as long as he knew his place and followed the party line while in front of the camera.
Vought international management at The Boys didn’t think Homelander was smart enough to be a devious planner because he wasn’t raised to be anything but a front man.
Vought International assumed that Homelander was more stupid than superficial and that he would never come to want the things that the wealth of the company could not provide him in The Boys, like a real family and a true love.
While the Boys character Homelander just wanted these things to reaffirm his own sense of worth, that awareness of something that was still missing was enough to fuel his slow rebellion against his bosses.
This led to him joining Stormfront to work against Vought in secret and his eventual collapse in the The Boys season 2 finale when he lost everything that really mattered to him.