I'm trying to use the nomenclature from the Glacier pricing page, where "transfer" is the verb to reference the cost per GB downloading the data from the remote provider. Glacier has an additional "retrieval" cost per GB that B2 and others do not (because they most likely have to physically retrieve a tape/HDD drive with your data on it).
Sorry I don't get it. With B2 I have to pay if I want to say download 100GB of data in B2. From what I read, you say this isn't so. But the pricing page state otherwise
https://aws.amazon.com/glacier/pricing/
https://www.backblaze.com/b2/cloud-storage-pricing.html