Biden wouldn’t be running if Trump wasn’t going to be the nominee . He has hinted or flat out admitted that . If Haley or DeSantis had the polling success and results early we would have had two primaries with younger candidates
There were a large number of Democrats running for POTUS in 2020. Besides Biden there were
26 others: (Michael Bennet, Bill de Blasio, Michael Bloomberg, Cory Booker, Steve Bullock, Pete Buttigieg, Juilan Castro, John Delaney, Mike Gravel, Kirsten Gillibrand, Amy Klobuchar, John Kickenlooper, Tulsi Gabbard, Kamala Harris, Jay Inslee, Wayne Messam, Beto O'Rourke, Deval Patrick, Tim Ryan, Bernie Sanders, Joe Sestak, Tom Steyer, Eric Swalwell, Elizabeth Warren, Marianne Williams, and Andrew Yang.)
Why did Joe Biden win? Because no one could top his experience and there wasn't a lot of name recognition with the other wanna-be Prez candidates. It was believed Joe had the best shot to get Trump's crazy ass OUT of the WH -- and he did..
If you're going to replace him, tell me who are you going to replace him with? And if you came up with a name, what would've been that person's POTUS war chest going into this campaign year?
It's EASY to whine and complain about "both" candidates, but, as Poolside said above, Joe' is running because somebody has to keep the crazies from reelecting Trump.