Although, if you have highly developed paranoia, then it is better for you not to use any services at all, because everywhere you see a catch and a keen eye of your big brother.
Yes, you are probably right. I prefer not to trust the Internet at all and only communicate with people I see and know.
Nevertheless, the story of the privnote.com fake site, although old,
is not safe from its repetition.
A similarly named phishing site that masqueraded as an anonymous note service was stealing bitcoins.
https://www.coindesk.com/markets/2020/06/15/encrypted-messaging-site-privnote-cloned-to-steal-bitcoin/