I disabled video caching/re-encoding on my #Mastodon instance. This allowed to purge ffmpeg and related libraries (128 packages in total, over 15% of all installed).
Why? Because ffmpeg and video attachments can easily trigger a DoS on a small server. Also, I never even watch any videos here.
https://github.com/mastodon/mastodon/issues/16496
Possibly also image processing imposes the same risk, but I haven't seen that happening yet. I wouldn't mind a text-only social media.