Microsoft has added basically the same functionality to Power Toys, called Run[0], taking heavy inspiration from Everything. But yeah this should be a built-in utility.
I'm pretty certain that everything doesn't use the NTFS journal[1].
My understanding is that everything uses the file open hooks provided for antivirus to maintain the index, which is why it appears instant.
Adding a millisecond to each open call is imperceptible to the user, and it takes less time than that if you return immediately and process the index update in the background.
Not quite. Run has plugins but the default file search still uses windows search. However, there is a third party plugin for powertoys run that integrates the everything search service.
It makes me wish I used a journaling filesystem on Linux too.