What Biden did was consistent with our foreign policy. A bipartisan group of senators, the EU, and IMF all wanted the prosecutor fired because he was obstructing corruption investigations. The Burisma investigation had been dead for a year at this point.
Trump on the other hand specifically mentioned the Bidens which does not serve our foreign policy goal of the country. He has been told by his aides and anyone who isn't a partisan hack that this was a debunked claim and he pushed it anyways. That's going to be key. Any legitimate concern about corruption goes out the window when they asked for a public announcement that the Bidens were being investigated. That serves no purpose but to smear Biden. Any competent corrupt person would have asked for a private investigation so as to not appear like a political hit job. Then if there actually is evidence of wrongdoing they could being charges and it would be legit. Beyond that the DoD already certified that "the" Ukraine had taken sufficient steps to combat corruption which was a requirement for the aid to have been granted in the first place.
Your arguments only work in a setting where you can get away with outright lying. In a court trial they wont be able to make baseless accusations and propaganda without being called out by the judge.