Wanting to return to the beginning of her scientific career, she spent a lot of time at the flea market.
At the beginning of her career, a researcher stored her data on floppy disks the contemporary local storage devices. After that, the data was neither accessed nor migrated to a modern memory format (CDs, DVDs, USB sticks, or external hard drives). The disks are still there and present and nicely labelled. Even if the data is still uncorrupted and complete today, her hardware for reading the disks simply no longer exists. So in order to get the appropriate hardware, she would have to be very lucky and find a device which is still functional: at a fleamarket, a storage room at the university or, in the worst case, at a museum.
The most important step to avoid this problem is to document the storage media used for past projects and continuously monitor the availability of complementary hardware. At the latest, when manufacturers announce that they will no longer install ports or drives in the newer generations of their devices, the data should be migrated to ensure bitstream preservation.
Upfront you can avoid trouble of this sort, if data is not stored exclusively on one medium, but, in keeping with the 3-2-1 rule, on several media types. The obsolescence of one type of memory device will then no longer directly result in an inability to access the data.