I finally went through all my Blu-Rays and began pulling the UV and digital codes and then entering; I previously had only redeemed the digital versions of Disney films for my kids.
Some digital codes/copies had expired since I sat on them so long, but as Rushmore said, they're pretty convenient when you're traveling, or if you don't feel like getting up and putting the physical disk in.
Also, there's an okay market for digital copies out there, they usually go for $3 or so a code (newer films or UHD codes can go for higher). I kind of wish I had tried to sell the digital copies I had, but this way I can share my digital library with my family without worrying about not getting my Blu-Rays back, or back in bad condition.