I'll just say a couple words in polite opposition to the idea that the slide is the final output

I
do understand this perspective, and lord knows that I love to look at slides with a loupe on a light-table. But...
-slide films scan very, very well. But you have to pay the bucks to get it done right; it is very difficult to get all that velvia has to offer using a flatbed or even a dedicated high-end film scanner. When it comes to velvia,
drum scan or no scan is my honest assessment. Okay that is a bit extreme, you
can get acceptable results with a lower end scan, but if you really want to have your socks knocked off, you simply have to drum. The good news is that you can admire your lovely slides with a high power loupe and sort through them very easily before deciding which ones to send to the drummer!
- slides can generate some great negatives. You can enlarge a slide considerably to b&w neg. film and then further enlarge that or contact print it. A medium format slide can generate a very credible LF neg. This is something that simply astounded me. On a whim I tried it with some 64T slide stuff that I had lying around. I kid you not: you can enlarge slide considerably without running into any grain at all, and the density range in the slide (Dmax to Dmin) makes for very quick and easy generation of a neg. The neg can be made on a nice pan film or paper, depends on what colour response you need. I have been playing with LF tmax for this kind of thing. Note that you can play some interesting colour-filtering games when you do this. Did you ever envy how the digital shooters can use photoshop's channel mixer to make b&w output? Envy no more, do it traditionally... with slide!
-slides can also be enlarged onto polaroid or fuji instant films, and the resulting emulsion can then be transferred or lifted. It's a good thing because getting a polaroid or fuji instant capture right in the field can be difficult.
-ilfochromes can still be done, and boy, they can be a jaw dropper, with saturation giving impact quite similar to a slide on a light-table. Unfortunately, I am not set up to do it and am very busy with other ventures, so my slide stuff typically winds up getting drummed and then light-jetted.
.. just a few reasons why the slide needn't be the final output. Though, again, I totally understand the perspective that a slide is itself a final product!