The price is not steep at all. This is a last resort solution, when all your other backups have failed and you need to retrieve your data. The idea is that you never need to restore it.
Glacier's primary business use is not as a backup solution but as a regulatory compliance tool. The idea is that you can guarantee regulatory bodies that whatever historical data that needed by law to be kept for x years has been preserved based on AWS' own claims of persistence.
The backup and store service is cheap, general outgoing bandwidth is very non-trivial as it also applies to every other service in AWS; It's designed to keep your data in and heavily discourage multi-cloud
