I have to add my voice to this too. I have been experiencing deteriorating battery life recently, including this draining of the battery when shutdown. Among other things, last morning, when I was at work, the SP4 shut down after ~3.5 hours of work where "work" involved using a Word document (backing up to OneDrive), Edge open with 2 tabs and connected to my work WiFI network. I have also tried to reset but with no positive results. Ran an energy report yesterday. See attached file.
Now I am thinking that perhaps after 2-odd years the SP4 battery has degraded to a point where either it has to be replaced or I buy a new machine.
Edit: Notice in the report that USB issue. I looked it up. Apparently, it is a relatively common issue and has been for a while. Also updated a battery report. There seems to a noticeable degradation of the battery going by this report.