All good in theory except when it fails
Having worked in an environment where desktops were replaced with thin clients I can verify that this sales pitch is complete bollocks. Having to have a rack server and thin client per user results in a higher machine cost. Poor setup management means that when something goes wrong with a machine and it requires a hard restart this can sometimes take hours in machine locating. With all computing VDI traffic now on the network for thousands of computers network administrators will enforce a high compression on the video transmission which results in a much degraded and pixelated video resolution which degrades user experience and most likely breaks work health & safety guidelines.