See and that's where we disagree. You see a scenario where Biden is corrupt thus giving credibility to the idea that Trumps' motives were reasonable (tell me if I'm wrong).
I see that as irrelevant. Why? It's like arguing that the validity of a search warrant is based on whether or not you found something incriminating. Either the process you followed was reasonable on it's face, or it wasn't. Either it's OK for POTUS to leverage official acts in support of his personal attorney's oppo research efforts, or it isn't. The results of that research is irrelevant to the underlying question of abuse of power.
Again, this is POTUS singling out and putting a US citizen (Hunter Biden) in the cross hairs of a foreign prosecutor, without any due process or protections in US law. It's a huge deal and reeks of the precise kind of corruption we are fighting in Ukraine, where whoever is in power gets to target their enemies.
I think there was enough smoke that it's not unreasonable to see if there was a fire. If hunter Biden is guilty of what is suggested, then it's the presidents job to use what resources he has to find out and that includes asking a foreign government to help look into it if the whole thing was based in their country. Every investigation begins with suspicion of a crime, this is no different.