Yes, and there are still some nice condition secondhand slide projectors out there. Braun Photo Technik in Germany still provide new 35mm slide projectors, for the time being. Jensen Diaprojektoren in Germany might still provide new, but I think quite expensive, medium format slide projectors.
But too much projection is not good for the film, and there are very, very few places that can still make analog transparency duplicates, and only slightly more places that can make transparencies from high-resolution scans (preferably photomultiplier tube drum scans to preserve the original film characteristics as well as possible). And of course, all of this can significantly increase the cost of using transparency film for projection.
Additionally, many labs have stopped offering slide mounting, even if they still do E-6 processing. So, one might have the additional cost and work of acquiring materials and mounting for projection.
All of this is not to disagree with your post, but just to point out that this has become more complicated nowadays.