Biden is not dropping out and was never going to drop out. Here's another helpful list of things which will not happen, which I'm sure Atlasians will nonetheless discuss as though they are real possibilities:
A contested convention
A cancelled/virtual convention
Replacing the incumbent VP
A third party candidate winning a state
A House contingent election (This is probably the most likely of the bunch. It still will not happen.)
The last time a VP was replaced for re-election to a second term was in the late 1800s. It is not going to happen. Every time somebody suggests replacing the VP as if it’s a realistic possibility, a puppy dies.
What a cute phrasing of things to remove the 3 times the VP was replaced in this past century.
1976 - Nelson Rockefeller removed and replaced with Bob Dole
1940 - John Nance Garner removed and replaced with Henry Wallace (if you want to say Garner was not removed insofar as he ran for President himself, fine, that still leaves...
1944 - Henry Wallace removed and replaced with Harry Truman
It was also privately discussed in 2004 and possibly replacing Dick Cheney.
It’s not “cute phrasing” to not count Rockefeller. He was the 25th amendment replacement VP to a replacement president. He was never on a ticket in the first place. He was an obvious placeholder pick.
Admittedly FDR is a more reasonable objection, but even then only 1944 counts. Garner clearly had no interest in remaining VP given he ran against Roosevelt, as you point out.
Wallace->Truman is the only VP replacement that really counts, "cute phrasing" aside.
I don’t believe for a second that there was actually a chance of Cheney being removed in 2004. People have allegedly “privately discussed” replacing every VP, but it never actually happens. The last time it was even a serious possibility (excluding the previously mentioned Agnew->Ford->Rockefeller->Dole shuffle 72-76) was Nixon in 56.
The 1976 thing, as I mentioned, gets at the problem that Congress would've never approved Dole or someone similar as Ford's VP in the first place. Rockefeller wasn't the VP Ford wanted and certainly wasn't one the GOP as a whole wanted.