For over twenty years, browsers broadly supported two features that were often convenient but sometimes accidentally invoked, leading to data loss.
The first feature was that hitting backspace would send the user back one page in their navigation history. This was convenient for those of us who keep our hands on the keyboard, but could lead to data loss– for instance, when filling out a web form, if focus accidentally left a text box, hitting backspace could result in navigating away from the form. (Some browsers tried to restore the contents of the form if the user understood what happened and hit “forward”, but this feature was imperfect and might not work for all forms). One of the browser UI leads complained about this behavior annually for a decade, and users periodically howled as they lost work. Finally, circa 2017, this feature was removed from Chrome and Microsoft Edge followed soon thereafter. If you happened to love the old behavior and accept the risk of data loss, you can restore it via extension.
If you do want to replace the content of the tab with the dropped file, you can simply drag/drop the file to the tab strip.
A small white arrow shows you which tab’s content will be replaced:
Dropping the file between tabs on the tab strip will insert a new tab at the selected location:
Chrome (85.0.4163/v84) and Microsoft Edge (85.0.541) include this change; it was also later merged to v84. Microsoft Edge Legacy didn’t support drop to navigate. Firefox still has the old behavior; the closest bug I could find is this one. Safari 13.1.1 still has the old behavior and replaces the content of the current tab with the local file. Safari Tech Preview 13.2 Release 108 instead navigates the tab to an error page (NSPOSIXErrorDomain:1 Operation not permitted”).