It all comes back to the definition of “privacy” and whether it is reasonable to expect that information, once posted to a publicly accessible forum, can be considered “private”.

Is it even reasonable to expect information that isn’t transmitted via some method which features end-to-end encryption to remain private?

Maybe I’m just old-school, but I’ve lived my life by the philosophy: “if it is private, don’t post it” Frankly, this should be the first thing we teach kids about the internet, IMHO.

A decentralized system is much more like email than people may be used to. I can ask someone to delete an email and they might even say they did, but it doesn’t mean it’s true.

If I delete content on Reddit it disappears from Reddit, because there’s only one and they control it. That doesn’t necessarily mean they deleted it either, but at least it doesn’t show up on the page anymore. That also ignores that Reddit has been scraped and archived for years and years by third parties, so there is a good possibility it still exists there too. (This scraping could eventually watch lemmy too).

A public forum is a public venue, best to assume the lack of privacy.

No shit it’s not private. This is the digital equivalent of shouting on a soapbox in public and then getting pissed if someone records or remembers it.