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Technically, you can modify system volume files/applications even in the newest macOS versions, but it becomes a whole lot more complicated since macOS Big Sur (11.0) onwards. However, for Mac OS X Catalina (10.15), it is a little more easier. More on that later, but first…
1. Possible solution (recommended):
Personally, I think modifying the system volume files is like taking a sledgehammer to crack a nut. Instead, I’d strongly encourage you first check if there’s any launch agent/launch daemon that is causing Podcasts app to run in the background?
To check this, run the command launchctl list in terminal and see if there’s any Podcast process that’s running (for example, it might be called com.apple.podcasts.PodcastContentService).
If you’ve found one, then just run launchctl unload com.apple.podcasts.PodcastContentService and it should unload the launch agent/launch daemon process for it. To check that it’s been unloaded just run launchctl list again and check that you don’t see the podcast process in the list. Note: If it fails to unload it, you may need to run the command using sudo, so for example, run sudo launchctl unload com.apple.podcasts.PodcastContentService. You’ll be prompted to type your admin password to run the command using sudo.
2. Modifying the System Volume (NOT recommended)
If the above solution doesn’t work, then there is a nuclear option involving modifying the system volume.
WARNING: Only perform the following tasks if you are comfortable with using terminal, disabling SIP and modifying system files. You should always back up your personal data as well. Modifying the system volume is a risk, so do it at your own peril.
Firstly, you’ll need to disable System Integrity Protection (SIP) through recovery mode, see here for instructions, then reboot. Once you’ve rebooted back to normal, you will need to mount the system volume before making the necessary system changes (i.e. deleting podcasts app). To mount the System volume (after SIP has been disabled and you’ve rebooted back to normal), you need to enter the following commands in Terminal:
sudo mount -uw /
killall Finder
You will be prompted to enter your admin password for your Mac in order to run the sudo command.
Once you’ve run the above commands, the System Volume should change from Read only to Read & Write in Finder, allowing you to delete/move/copy the podcasts app and modify a whole slew of other system files all through Finder (i.e. no need to use Terminal for this part). Caution: Modifying system files/deleting applications can break other core functionality of macOS, so you might need to do some independent research on what consequences (if there are any) would deleting the podcast app have on your Mac.
Once you have finished making the changes, just restart your mac and the System volume should be unmounted by itself. Caution: SIP is still disabled, so if you are finished with modifying system files, you are strongly encouraged to enable SIP again by going into recovery mode and follow the reverse instructions as given in the above link.
Once all of that has been done, the podcast app will no longer be available on your Mac.
Note: There are a number of important caveats you should be aware of:
- I don’t believe there is a way to download and reinstall a single system app, so you’ll most likely need to reinstall the entire operating system from scratch if you want to use the Podcasts app again at a later date.
- Doing a minor software update (i.e. going from 10.15.1 to 10.15.2) might reinstall the Podcasts app again, but you can just follow the same process as above, as long as it is still in Mac OS X 10.15 Catalina.
- However, if you were to install a major operating system release (i.e. going from Mac OS X 10.15 Catalina to macOS 11 Big Sur or macOS 12 Monterey, macOS 13 Ventura, etc.), then the Podcast app will reinstall itself and deleting/modifying system volume files is a whole lot more complicated in macOS 11+ due to the Signed System Volume (SSV) Apple introduced in macOS 11 Big Sur. More info about SSV can be found in Apple’s support article here.
- To modify System Volume files in macOS 11+, you will be required to disable SIP, disable the cryptographic verification, mounting the System Volume, make the required System Volume changes, then sealing/blessing a new snapshot of the System volume. Without blessing the snapshot of the System Volume’s changes, the Mac will fail to boot until the snapshot has been blessed (I think you can do this within recovery mode though). More information on how does SSV interact with modifying System Volume files in macOS 11+ can be found in this blog.
In summary, I would first recommend you try the first possible solution, and check if there’s a background process that is causing Podcasts to open. Then try unload the relevant process using launchctl unload command.
Failing this, then you can consider modifying the system volume, but I highly do not recommend you do this unless you are fully aware of the consequences of modifying system volume files, and be prepared to reinstall Mac OS X Catalina 10.15 from scratch if it affects the operating system after deleting podcasts app.
You should always back up all your data before modifying the system volume, because although it is unlikely to affect the data volume portion of your Mac’s internal drive, you may need to reformat the entire internal drive when reinstalling Mac OS X Catalina (but this is really the worse case scenario).
Good luck!