That just means you have to be smart about retention. You don't need permanent logs of every request that hits your application. (And, even if you do for some reason, archiving logs older than X days to colder, cheaper storage still probably makes sense.)
It's not a problem of retention. It's a problem caused by the sheer volume of data. Telemetry data must be stored for over N days in order to be useful, and if you decide to track telemetry data of all tyoes involved in "wide events" throughout this period then you need to make room to persist it. If you're bundling efficient telemetry types like metrics with data intensive telemetry like logs in events them the data you need to store quickly adds up.
deleting data early after moving it to cold storage, has additional costs.
sc1 HDD-based volumes are cheaper than S3, while st1-based volumes are only 2x more expensive than S3 ( https://aws.amazon.com/ebs/pricing/ ). So there is little economical sense in using S3 over HDD-based persistent volumes.