That may be your point, but it isn't one that anyone has disputed, is it? The point under dispute is whether Biden or Trump would be likely to commit an illegal "official" act. Most of us think that Trump would be far more likely than Biden to do that, since Trump has already been convicted of illegal behavior by unanimous juries. The Supreme Court statement on immunity was extremely muddled, because it did not set a legal standard for what an "official act" is, leaving it up to presidents to use their imaginations. Trump's imagination seems considerably more flexible than Biden's on that score, and Trump likely believes, as do most commentators, that the SCOTUS directive was constructed with him in mind.