What is the purpose of logs for activities in civicrm_log table?

I am struggling with a large database and try to find ways to reduce data mess. I really wonder why there is no scheduled job to delete old log entries from civicrm_log but this is not my question. Diving into this data I found out that there log entries created everytime an activity was created or updated. But it seems to me that these logs are never shown to admin in the backend?! For contacts there is a tab for the logs but for activities I could not find any page where the logs for an activity are listed.

Is there a way to avoid log creation for activities? Is there any way to list these logs to users or what is the reason to create these logs?