@galacticstone well...everything is nuanced, friend. Posts that aren't "local" are only cached. It does take up the same amount of storage however.
Also, a LOT of Fedi instances use block storage, which costs money per GB, per month. So non-local posts and media that's attached are sometimes cleared for space and money.
Though, not ALL Fedi instances clear it all the time, including .social because I guess they want to preserve Fedi as much as they canx