I quite liked the old Safari for Windows. It felt like bringing over a slice of the Apple ecosystem to the common Windows XP or Vista desktop. You could run Safari and iTunes and have decent parity with (then) Mac OS X for the most common use cases.
I was probably the only household within the 200 km radius back in 2009 that was using Safari to browse the web and iTunes to listen to web radio from around the world, all on a Windows Vista machine
They likely discontinued because there was barely any interest. Likely the only reason Safari has any use is that it's the default on MacOS and monopolized on i*OS.
With what Google has been doing to Chrome, and given that I use iOS, I would definitely use Safari on Windows cause I trust Apple more with Privacy, plus the session/tabs/auth/bookmark/applepay etc integration between my phone and Windows laptop/desktop would be great!