You do end up having to roll your own stuff that the vendors like Synology provide. Depending on your ISP and router, for example, a reliable way to manage it

You do end up having to roll your own stuff that the vendors like Synology provide. Depending on your ISP and router, for example, a reliable way to manage it remotely isn't always easy. The Synology setup figures out how to punch holes, make reverse tunnels to a Synology owned jump box, etc, in a way that you don't have to think about...it just works. Similar for the mobile apps to sync photos, integration with various 3rd party offsite backups, etc. All possible to roll your own, of course, but time is money.