1. The reason to replace him is that he’s not doing great in the polls and the pet issue plaguing him went on full display. And it’d be trivial to get a candidate that doesn’t share his one practical issue.
2. Of course I knew Biden was old. Meanwhile, my great-grandpa was building grape arbors and digging trenches at 96, and my wife’s grandpa is still enjoying a life as professor emeritus of photojournalism at 94. I know (knew) people way older than Biden who had way more vitality. Age alone isn’t the issue.
3. Biden’s optics are clearly a problem, even if his admin has been great. You can have more than one problem simultaneously.
4. a) you’re dangerously close to just name-calling and I gotta say that I don’t appreciate it. b) Sort of back to (3), it’s almost certainly not an issue with Democratic voters, but rather the unfortunately apathetic and under-informed independent/unregistered voters.
5. AOC and Bernie I agree with you on those two (though personally I’d vote for Sanders on policy and am hopeful AOC becomes a heavyweight in a few years as she continues to gain achievments). But there’s a huge difference between what «plagues» Biden and what «plagues» Harris and Buttigieg. You can’t be too black, female, or gay to be President in any practical sense.