MicrosoftNothing grinds my gears more than when somebody has a legitimate complaint about a missing feature, somebody else says "you shouldn't be using it." The fact is PSTs have many valid uses. They are a very easy, convenient storage of mail, calendar, and contact data. We use them from time to time as a quick way to store offline mail data that we don't want to waste time or effort keeping in the cloud. Further, we have retention requirements that require OFFLINE AIR GAPPED storage of data. PSTs make that dead easy. And for retrieval, all you need is a thumb drive and Outlook.
If you moved away from PSTs, wonderful, I agree it's not best practice to use them for storing Exchange Online data (although, the dirty little secret there is that OSTs, the local cache, are just fancy PSTs). But PSTs remain useful.
