You're forgetting one thing.
Biden (if he wins) will inherit a messy divided America, a pandemic torn country which by then would be too widespread, a tanking economic, the trade war, Russia, an alienated Europe, a pissed off world. On top of that he'll still have to deal with the 32% something of Trump supporter that exists in the government, senate, and house. Even if they're majority you really can't outright instruct them GOP senators to do as they wish.
All the GOP needs to do is point the finger at Biden not delivering and the gullible Americans will be back to voting Republican