I find it fills the band sound out more, I use fingers mostly but also a pick and mute the strings with my RH palm on a couple of songs where I want that old fashioned flat wound sound.
I think most of us spent the first week on fretless sliding around, after that I started just to use it for playing properly but with a different feel/sound.
After a few years of experimenting (having tried and moved on from active acoustic,Precision, MM style) I settled on passive jazz as my weapon of choice.
What I hate is when (usually none bass players ) say " have you trued that with a chorus pedal?" - No, I don't wish to sound like every band from the 1980's that I hated.
And remember - the slide is still there for when you absolutely need it.