Similar to Ryan and Tudor, DT is my filing system; everything gets thrown into it. DT’s search/find function IMHO is markedly superior to that of Spotlight and that was the use by which I justified the cost until one of MPU workflow episodes with Gabe Weatherhead.
I’m an indiscriminate squirrel in downloading stuff that I might want to watch or listen to one day - all stored on a heap of external drives. When I heard Gabe talk about indexing external drives; I quite literally had to pull-over to the side of the road while I re-listened to his comments and mulled over possible use.
Now, for example, a piece of cake to find podcasts among the 45,000+ on the podcast drives. Better still, the links DT shows to related material means that I can deep dive into a particular topic of current interest. Same applies to reading material, webpages, articles etc.