For best practice, my personal recommendation would be to not have any service public facing besides a VPN that requires MFA. segment self hosted services into separate VLANs based on how sensitive the content is. Disallow all traffic between VLANs unless required and only allow based on port number, specific resources needed. Don’t forgot to disable outgoing Internet access unless required. Devices like Chinese made video cameras should never have an Internet connection.
My network looks something like: home vlan, work vlan, Netflix \ hulu streaming devices, cctv, wireless work, wireless home, wireless guest, iot, servers, network management. Would be way overkill for vast majority of people, but I would be hypocritical not to considering what I do and I do have a different threat profile than most.
Another thought: self hosted through VPN with MFA and nothing public facing is probably safer than cloud as long as you have cold backups.
If you think anything on the Internet can ever be forgotten… Your going to have a bad time. Passwords, one of the most protected data types, are compiled from beaches into huge databases so that hackers can use them to try to log into website. There are literally dozens of not hundreds of those password databases on the public Internet to be downloaded, not to mention private or dark web collections. If passwords are not safe, what makes you think publicly available social media would be any different?
Even if somehow the whole federation agreed to purge all post every year, things like the Internet archive and Google cache of pages would retain the data.