I dunno, I think it was mostly that they wanted joe to step down later on in order to justify not having a primary, and dispelling a populist candidate, like tim walz may have been, a populist candidate which goes against the interests of the donors, and could've still probably gone through with a ton of funding and a groundswell of support regardless (see: kamala getting 1 billion dollars), from the running. Then, they can run kamala by default, and it doesn't matter whether or not she really wins or loses, as she's still campaigning on basically the platform that the republicans of 2016 were running on. I dunno so much if the time was the problem, other countries have full elections in as much time, I think the real problem was the electoral calculus that runs everything the scenes, as it has always been, and I think a lot of people got their brain cooked by brat summer and coconut memes into believing this was somehow going to be any better than 2016.