Podcasts downloads every episode, and TV keeps what you watched

Both of these apps download content in the background by default, and both keep it after you have finished with it. Neither is enormous on its own, and together on a Mac that has had them for years they are worth a look.

Where the files are

du -sh ~/Library/Group\ Containers/*podcasts* \
  ~/Library/Containers/com.apple.podcasts \
  ~/Library/Containers/com.apple.TV 2>/dev/null | sort -h

Both keep their media inside containers rather than in your Music or Movies folders, which is why nothing you do in Finder ever reveals them and why they land in System Data on the storage screen.

Podcasts, and the setting that matters

By default the app downloads new episodes of shows you follow and keeps played episodes for a period. An hour of audio is modest, a daily show over a year is not, and video podcasts are in a different league again.

In the app's settings there are two controls worth setting once: how many episodes to keep, and whether to delete played episodes automatically. Both turn an unbounded folder into a bounded one, which is the same lesson as Telegram's cache limit.

TV, and the films you already watched

Downloaded films and episodes are the largest single files either app produces, at several gigabytes for a film in high quality. The app has its own downloads list, and removing an item there is the correct way to do it, since it keeps the entitlement and simply removes the file.

Rented films delete themselves when the rental expires. Purchased ones stay until you remove them, and they can be downloaded again at no cost, which makes them one of the safer things to delete on a full Mac.

Checking what is worth doing

find ~/Library/Containers/com.apple.TV \
  ~/Library/Group\ Containers/*podcasts* -type f -size +200M \
  -exec ls -lh {} + 2>/dev/null | sort -k5 -h | tail -10

If that prints nothing, these apps are not your problem and the space is elsewhere: the order to free 100 GB works through the categories that usually are.