I think your idea is partially right, but I think theres another angle: self preservation. Hes in up to his plugs in the anti-Trump shenanigans, and a lot of it ties into the deals his son had with the Ukraine and the fact that Biden actually publicly threatened to withhold foreign aid from them if they didnt go along with his desired candidate in their elections. This is all going to come out if a full investigation is conducted.
On the DNC level, I think the plan is for him to draw support and then hand it off to some other candidate (probably Michelle Obama). On the Joe Biden level, I think its to document his irrationality, so that he can then plead illness, senility, or whatever when his past catches up with him.
His dealings with Hunter in Ukraine and other investment deals are certainly going to affect those who might consider a vote. He’s had decades of using his political positions to gain inside information both here and abroad. If those cash cows start being affected he’ll give pause along the way.
We agree then he’s not in this to win the presidency....but as you stated to hand off his support to another candidate. which I can’t imagine though it would be Michelle Obama?
If Michelle My Belle appears as the Dem’s savior, DJT can ask us if we all want to go back to the BHO economy. Not bloody likely.