I wouldn't be surprised if both Trump and Biden die of natural causes in September/October, throwing the November election into chaos as no one has anyone to vote for anymore.
It's just the sort of chaos this timeline seems to crave.
It might be an okay outcome. No T means split R vote and no B means Kamala becomes first female president. Maybe she runs again, maybe there's a new nominee.
I don't think much changes other than losing the spearhead of the MAGA bullshit, although someone will inevitably take that place.
Thankfully I don’t have that worry with Biden. He’s quite fit and healthy, in great shape considering his age. So he has far great chances of surviving each day.
Being fit and healthy doesn't really exclude much at that age, anything can happen.
My grandpa was fit as a fiddle at 86 outside gardening everyday, then got kidney cancer and a bunch of other stuff all at once, pretty much bedridden within a year.