Locate doesn't do what Windows 10 does with search (locate just does filenames). Plus it's slower than Windows 10 nor does it give the most relevant results first.

Windows 10 experience: you press start then type in a few letters and you already get good relevant results. This completely different from locate!

Hasn't it been replaced by slocate, mlocate, tlocate or another variant since ?

Yes, and there were a few implementations from different groups, as you would expect. I'm typing this on a current Arch and locate, mlocate and slocate are all available from the mlocate package.

They are most likely symlinks to mlocate

I doubt very much my Slackware 2.0 copy had locate.

I've used locate ever since I used Linux, my first distro was Slackware downloaded to oh so many stiffies (the hard plastic successor to floppies) circa 1994, I certainly won't die in a ditch insisting it was in there but I would be very surprised if it wasn't.

I'll put in somewhere in the middle of my "mildly interesting to maybe know" research list.