These are usenet data sales. Usenet is an old network of distributed discussion groups that predates the web by about a decade. It contains a large trove of media and software - particularly older media and software - that is easy to acccess because it’s not a P2P network that is reliant others keeping their shares alive.
Many usenet providers offer bulk data plans, rather than continual subscriptions. This means you buy x GB of bandwidth, and you use it on whatever time table you like.These are great if you don’t do a lot of downloading, or if you’re just trying it out, or if you’re using usenet as a secondary or tertiary source for things.
Like the fesiverse, most usenet providers do not provide a full view of the whole network, so it can also be good to have a secondary provider that has different retention policies, so a lot of usenet users will buy these data blocks for that purpose, as well.
It’s not a community setting or feature. It’s a fact of the internet.
If you publish something to someone else’s website, you no longer have any control over it. And federation means publishing your content on thousands of websites, many of them not even running the same software. Your comments are out there on mbin sites, Friendica sites, Hubzilla sites, Mastodon sites, Misskey sites, and many others. Someone’s pribably got a custom web server they developed, slapped some ActivityPub inside of it, and didn’t bother to make it even understand delete requests.
This is the internet. It is public, and it is forever. You really need to treat it as such.