I will stick my neck out, then go out on a limb (to mix metaphors):
Biden's presidency will last less than 2 years. It will probably be shorter than 18 months.
It is entirely speculation on my part, but I think that Biden didn't want to get into the race before the primary season but was talked into it late by promises that after the election, he could drop out, resigning for health reason. I really think he has age-related cognitive issues. It happened to President Reagan. It is obviously happening to Senator Feinstein.
Now it looks like hBiden will in fact be sworn in along with Harris in Feb. But it is my guess (and only my guess) that he is liking the idea of being The President Of The United States. So now the behind-the-scenes power brokers are laying the groundwork to have him forced to resign, either for health reasons or for some corruption involving His son and/or brother perhaps involving China.
OK, so this reads a bit like Grishem novel, but who would hve bought a script based on the events of 2019-2020?