Do we actually know what the reality was? As far as I'm aware of the facts, Hunter was getting paid at least $50k per month by the Ukrainian company (Burisma) without having anything obvious to offer them other than the connection to his father who was handling the allocation of aid to Ukraine. The Ukrainian prosecutor Shokin was investigating Burisma. There were claims that Shokin was corrupt amid complaints that he wasn't making progress on the investigation of Burisma. Biden threatened to withhold aid unless Shokin was fired. Shokin was forced out in Feb 2016. The case against Bursima was dropped in 2017. In 2018 the decision to annul the case was overruled and the oligarch behind Burisma fled the country. Trump was then impeached over the phone call pushing Ukraine to investigate this.
Biden was accused of having a conflict of interest as his decisions directly benefitted the company that was paying his son $50k a month for no readily discernible reason. Biden claimed that there was no conflict because he never talked to his son about his overseas business. If these emails pan out, then we see in fact his son was connecting people within Burisma to Joe Biden, undermining Joe Biden's claims a bit.
I don't think it is exactly proved that Biden was doing anything corrupt here, but I don't understand your certainty that he wasn't.