Sound familiar, anyone? Just over a month ago Dell reported that addressing the removal of S3 sleep was next on its agenda for the XPS 15 9570. Disappointingly, but perhaps unsurprisingly, the company has seemingly u-turned on this promise.
https://www.notebookcheck.net/Dell-backtracks-on-XPS-15-9570-S3-sleep-fix.423082.0.html