In 2019 the total size of the text stored by Reddit was only 50TB. A Petabyte of data in cold storage is only 12k a year so even if they 500x in size since 2019 (very unlikely) it’s a drop in their ARR. given they sell the data for advertising and for AI, they are not deleting it. Reddit also self hosts a lot of their infra (they used to present their architecture at kubecon) so the storage costs would be even lower