We work with a lot of newly released edits of original older music from the 70s and 80s. Usually a client asks us for help to beat grid, time edit or warp them to get them to behave in their DAW or DJ software. After further investigation, we almost always find that the producer of the new edit hasn't edited the timing of the original track that they have sampled or the resulting samples that are in their shiny new release. This always results in a track with a drifting tempo that won't automate alongside other tracks easily and needs BPM editing work.
DJ software has developed into such a sophisticated solution that it is changing the way we all look at DJing. When I first started mixing in the 90's, I used 1210s; these were fun, but also a lot of work. There was a constant need to press and push records to maintain the near perfect alignment of both tracks for smooth mixes. You could get it so that the track you were bringing in needed a minimal amount of manipulation during the actual mixing process, but that would take time and effort. The result of this way of mixing is, of course, the development of a finely tuned ear for lining up tunes, but the down side was the limited available time to think about the actual performance in the moment.