When you remove a snapshot, Ceph has to delete all the objects which have been created due to the copy on write nature of the snapshot process. From Ceph 10.2.8 onward, there is an improved OSD setting called osd_snap_trim_sleep, which makes Ceph wait for the specified number of settings between the trimming of each snapshot object. This ensures that the backing object store does not become overloaded.
Although this setting was available in previous jewel releases, its behavior was not the same and should not be used.