Definitely could have lost some weight and trained more sensibly for 2019. I was working too hard to get a khound, which ended up being a significant part of my dnf.
I think the most important thing about equipment is that it is reliable and familiar. Virtually every bike that completed PBP in 2019 was equipped with 700c tires and a derailleur drivetrain. Bayes theorem says that virtually every PBP failure is going to involve 700c tires and a derailleur drivetrain.