> I think GitHub just have a cap of 100MB on any single individual file

There's a 100MB limit on the size of a push, which also limits the size of a any single git object (i.e. file) to 100MB too. However GitHub supports LFS for large files, and their documentation says to use LFS for files over 100MB:

https://docs.github.com/en/repositories/working-with-files/m...

> GitHub blocks pushes that exceed 100 MB.

> To track files beyond this limit, you must use Git Large File Storage (Git LFS).

https://docs.github.com/en/billing/managing-billing-for-git-...

According to my own GitHub account ( https://github.com/account/billing/data/upgrade?packs=1 ), I'm paying $37/yr for 600GB LFS storage on top of my existing GitHub Pro subscription.