Nobody loves that Joe Biden is 81. It would be great if he was 35. But you know what I really dislike? Authoritarianism. So I humbly beseech people to get a goddamn grip.
All of this also seems to show that neither party didn't learn from RFK's assassination and have a plan in place if something happens to the nominee or presumptive. Forget the two men we have today - you can have a 37 year old nominee that gets hit by a car or something and can't continue - there just seems to be no plan B. (And I know RFK wasn't the nominee at the time - but it should have made them all realize, that hey, we need a plan just in case something happens to a nominee)
Plus, I haven't got a clue what it should be or even could be - for one, the whole brokered convention idea might have worked 100+ years ago, but it sure as hell won't in today's day and age. But at least if you have an incumbent running, it can help there - you push up the VP since when we vote for president, we are always also voting for VP. Other than that, I definitely don't know, but I'm not the one that needs to come up with the plans, they are!