It's not too late.
For over a year I have been saying, "No, there's a third possibility: someone else could run for the Democrats."
The DNC squashed any possibility of primaries, but there is still the convention, still a chance to get a young, fresh candidate.
If, God forbid, Biden loses, the blame will squarely be with the Democrats, but as we saw in 2016, they won't learn a darned thing from this.