Keep in mind, the cost of a vintage item on EBay may have nothing to do with how useful it is. People pay lots of money for lots of things for lots of reasons. I once paid nearly 400 dollars for an item I used precisely never, and sold it after 3 years of moving it out of my way. Anyhow like you said, they can be useful. But I don’t see needing a drawer full of them. I use dividers the same way others have mentioned. Just not often, and if I didn’t have them I wouldn’t be stalled. I use a combination square for a lot of layout type work. But again, if I didn’t have them, I wouldn’t lose any time. Contrast that with dial or digital calipers, which I couldn’t do without. Super useful gadget...20 bucks will buy you a set that are as accurate as most of us need. A micrometer set that ranges from 0-6 inches would be the only way to continue if I didn’t have calipers. Calipers that indicate measurements in thousandths of an inch, in my opinion, essential.
Btw, I had to look it up, but apparently the terms divider and caliper seem to be interchangeable.