recertified drives are often just old larger drives with the bad parts programmed out of the controller.
larger sizes (say 512gb)... those that fail or don't have enough good slack at 512gb and get rebranded as 500gb...or 250gb drives that fail are rebranded as 200 or 128gb drives, and so on.
i wouldn't worry too much about the drive being "worn out"... if the drive detects the flash bit is wore out, it'll re-write data to a slack area. recertified drives would likely have a heap load of slack since they were formerly much bigger drives.
who knows, perhaps their recertification process involves replacing the bad NAND

all kinds of shenanigans go on with companies. i used to get recertified drives as warranty replacements if smaller sizes were not available...and I'd get them in all sorts of weird sizes not commonly seen. (450gb 340gb etc) these are obviously larger drives with firmware ID'ing them as a smaller drive to "write out" the bad areas so they don't get used.
as long as you aren't trying to keep your kids baby photos safe on it, give 'er... otherwise buy new.