PrivacyTools
It is not open-source, but there discord is open to alot of known privacy people and they enjoy it alot. they recently released a ios and andriod app for it. you can choose to store your paste on skiff servers or ipfs. both are end to end encrypted zero knowledge and they can't see your account anyways. if you do not like it, you can request to delete your account also and all it's data...