Both S3 and Google offer file storage where you can set that it can't be overwritten or deleted until a certain date. So you get the best of offline and online storage.
If you have a decent connection, cloud storage is hard to beat.
What does that even mean? If I don't have to restore, /dev/null will be even cheaper!
At $4/TB why would I pick this over blackblaze B2 which is $5/TB (pretty basically the same) but works like live normal block storage instead of taking hours to retrieve (or minutes if you pay extra)?
Moreover the download cost from glacier to AWS is $0.02/GB plus at least $0.003/GB in retrieval costs (or $0.09/GB to $0.05/GB to the internet), while the download cost from blackblaze to the internet is only $0.01/GB and is free if it's to many of the members of the bandwidth alliance (notably including cloudflare).
I'd have to be looking at many petabytes of data before the miniscule cost savings of glacier data that I actually don't touch is worth it. Or I guess if the data was already in AWS and the egress to blackblaze was going to be too expensive to be worth it.
Does Backblaze B2 have multi-site redundancy? We have our S3 buckets automagically replicated to a different AZ. That was a must have since we're highly regulated, and our backups need to persist for over 7 years.