I have multiple devices, like most people today.
They run a multitude of operating systems, including Linux (and its various distributions), Windows, Android, and possibly even Apple products.
The "old school way" (or almost how I perceived it while growing up) was that you had a personal main computer, which you used for most things; or at least you tried to keep everything important stored on this computer's hard drive, so you moved all important files via USB sticks, emails, cloud services, etc. And then you made backup copies of this computer.
Fast forward to the current year (2020), and now I'm wondering what is the best, or at least the most common, way of running your business assuming you have multiple computers and devices, and that each of them is used to generate important data, or must access it. I can quickly think of some diagrams, and I will present them here. I am also very allergic to depend on other parties on my data management / storage, so commercial cloud services are prohibited, even if they could be a great solution for this.
1) Decide on a "main device" / central point on which you synchronize all your data.
example: a desktop computer in your home that has its own storage, or some sort of storage solution (NAS, server?). And then, if you create important data on a device, you somehow transfer it to this centralized location. And also if you need to get / use data, you get it here. So your computers / devices act as "end devices" and the actual data is kept in a central location (with the necessary duplicates, etc. of course).
2) All your devices with separate storage.
example: you have a desktop computer that contains data, a laptop computer that has different data, a second laptop computer that contains different items again, a tablet that contains different items again … This option appears to be management chaos, and I can't think of how we could keep things in order, or remember where specific data is.
3) All your devices synchronized
example: as above, you create and store data on all your devices, but you keep them synchronized via the software automatically / manually: This would limit your storage as the smallest storage on your "synchronization network", and if a synchronization goes wrong, it could cause a "bad synchronization hell".
So my question is: What is the standard way to manage data on multiple devices?