It's great you added file locksmith to powertoys but that should be a built in OS feature for many, many years now.

The actual interesting discussion, to me, is why Microsoft won't show WHO is dangling the handle open when the user tries to interact with a file via Windows' UI. To understand that, we have to look at a BSOD change Microsoft made in Windows 8:

In Windows 2K, XP, Vista, and 7 the BSOD would tell you exactly WHO was causing your BSOD (i.e. which module). Which was incredibly helpful, when you could see it was a e.g. Creative sound driver, or Nvidia graphics driver. Then in Windows 8/8.1 they went to the "sad face" simplified BSOD screen. From then on in order to see which module it originated in, you had to load the mini-dump into WinDbg (which almost no users would/could do).

What I am saying is: Microsoft went out of their way to shield their partners (OEMs/hardware vendors) from criticism with that BSOD UI change. So it seems unlikely they'd make a change to the "File Locked" UI that would essentially do the same thing: Open up their partners to criticism for their [bad] software (e.g. anti-virus/anti-malware/corporate compliance/etc).

Then tack on that Microsoft's own software may be some misbehaving software; and they'd essentially be telling on themselves. OneDrive in particular, I've seen in that list a lot (but I could write paragraphs on what a turd/abandonware OneDrive is).