do i think biden should drop out?
not exactly.
however, i think that prominent democrats should to try to force him out, and see if they can. the only conceivable alternative is kamala harris, who is unlikely to win an election against anybody. yet, the reality is that she's almost certainly either going to take over when biden dies, or have to use section 4 of the 25th amendment when biden embarrasses himself one moment too far. the latter is a real possibility.
a democratic purist may suggest that, as harris is certain to take over, it is harris that should run at the top of the ticket. ok. there's an argument for that. the flip side is that biden has, to this point, been the stronger candidate. that might be changing.
if the democrats think that harris should be at the top of the ticket, they should mutiny and force biden out. however, i don't see any reason to suggest he should step down.