I don't think he'll be that far behind should he announce, simply because of name recognition. Most of the candidates this time around are pretty new on the national scene (eg Harris), or, even if they'd been around for a while, didn't have great name recognition until recently (eg Sanders). Maybe Warren is the best of the lot on that front, and even then she didn't make a mark until Dodd-Frank, thanks to her getting the CFPB in there.
Biden's been a figure in national US politics for decades, so he starts from the front as far as "I know that name" is concerned.
Plus his presence in national politics for so long means he's built up a huge network, so raising money shouldn't be too much of an issue, unless all those big donors have already fully cast their lot in with others like O'Rourke or Harris, perhaps.