I think the point is that most of this, other than buying extra hard drives, is solved by having a decent FOSS project. For example, an OS that has a nextcloud

I think the point is that most of this, other than buying extra hard drives, is solved by having a decent FOSS project. For example, an OS that has a nextcloud-like suite of services, and a very easy to use GUI to enable a VPN / mesh network for all of your devices pretty much removes much of the concerns you mentioned regarding networking/firewalls/etc.