Wait, are you really comparing a personal NAS lying somewhere in your office (or even DC) with a proper cloud storage system? what about redundance, reliability

Wait, are you really comparing a personal NAS lying somewhere in your office (or even DC) with a proper cloud storage system? what about redundance, reliability, downtime, just to name a few? a personal NAS is obviously a very good solution for a limited subset of use cases compared to something like dropbox or Google drive, but not a definitive alternative solution, in my opinion.