I don't understand where advice like finishing the book is optional comes from. Anyone who's ever written anything of some length and gone through the publishing process with copy editors would recognize that stories are told in coherent pieces. If a book isn't meant to be finished it isn't meant to be read. Move on.
Am I the only person who thinks this isn't a big deal? Honestly get is not a personal storage space, it's capped at 1GB.
As a service anything I build privately will need more than three collaborators. Especially for things which are traditionally kept secret like academic software.
Maybe this might help freelancers but proliferationf private repos with very few contributors is an anti pattern.
Gitlab is still the clear winner for private use while Github remains the most active for public repos.